ArticlePDF Available

Cyclin D1 and PRAME expression in distinguishing melanoma in situ from benign melanocytic proliferation of the nail unit

Authors:

Abstract and Figures

Background Distinguishing benign lesion from early malignancy in melanocytic lesions of the nail unit still remains a diagnostic challenge, both clinically and histopathologically. While several immunohistochemistry (IHC) stainings have been suggested to help discriminate benign subungual melanocytic proliferation (SMP) and subungual melanoma in situ (MIS), the diagnostic utility of IHC staining for cyclin D1 and PRAME has not been thoroughly investigated in melanocytic lesions of nail unit. Methods This retrospective study included cases of benign SMP and subungual MIS confirmed by biopsy at Asan Medical Center from January 2016 to December 2020. Cases of melanocytic activation without proliferation and melanoma where dermal invasion was identified were excluded. Cyclin D1 and PRAME expression was assessed by counting proportion of melanocytes with nuclear positivity under 200x magnification. Results A total of 14 patients with benign SMP and 13 patients with subungual MIS were included in this study. 11 patients with benign SMP (71.4%) and 5 patients with subungual MIS (38.5%) showed > 60% nuclear immunostaining for cyclin D1, respectively. While 13 patients with benign SMP (92.9%) showed totally negative staining for PRAME, 10 patients with subungual MIS (76.9%) exhibited > 50% nuclear immunostaining for PRAME. Using the cutoff of 10%, PRAME exhibited good overall discrimination between benign SMP and subungual MIS (AUC = 0.849, 95% CI = 0.659–0.957). Conclusions This study suggests that PRAME IHC staining as a reliable discriminator in distinguishing subungual MIS from benign SMP.
This content is subject to copyright. Terms and conditions apply.
R E S E A R C H Open Access
Cyclin D1 and PRAME expression in
distinguishing melanoma in situ from
benign melanocytic proliferation of the nail
unit
Young Jae Kim
1
, Chang Jin Jung
1
, Hyoungmin Na
1
, Woo Jin Lee
1
, Sung Eun Chang
1
, Mi Woo Lee
1
,
Chan-Sik Park
2
, Youngkyoung Lim
1,3*
and Chong Hyun Won
1*
Abstract
Background: Distinguishing benign lesion from early malignancy in melanocytic lesions of the nail unit still
remains a diagnostic challenge, both clinically and histopathologically. While several immunohistochemistry (IHC)
stainings have been suggested to help discriminate benign subungual melanocytic proliferation (SMP) and
subungual melanoma in situ (MIS), the diagnostic utility of IHC staining for cyclin D1 and PRAME has not been
thoroughly investigated in melanocytic lesions of nail unit.
Methods: This retrospective study included cases of benign SMP and subungual MIS confirmed by biopsy at Asan
Medical Center from January 2016 to December 2020. Cases of melanocytic activation without proliferation and
melanoma where dermal invasion was identified were excluded. Cyclin D1 and PRAME expression was assessed by
counting proportion of melanocytes with nuclear positivity under 200x magnification.
Results: A total of 14 patients with benign SMP and 13 patients with subungual MIS were included in this study. 11
patients with benign SMP (71.4%) and 5 patients with subungual MIS (38.5%) showed > 60% nuclear
immunostaining for cyclin D1, respectively. While 13 patients with benign SMP (92.9%) showed totally negative
staining for PRAME, 10 patients with subungual MIS (76.9%) exhibited > 50% nuclear immunostaining for PRAME.
Using the cutoff of 10%, PRAME exhibited good overall discrimination between benign SMP and subungual MIS
(AUC = 0.849, 95% CI = 0.6590.957).
Conclusions: This study suggests that PRAME IHC staining as a reliable discriminator in distinguishing subungual
MIS from benign SMP.
Keywords: Cyclin D1, Melanoma, Nail, PRAME, Retrospective study
© The Author(s). 2022 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License,
which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give
appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if
changes were made. The images or other third party material in this article are included in the article's Creative Commons
licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons
licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain
permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the
data made available in this article, unless otherwise stated in a credit line to the data.
* Correspondence: ykwh01232@naver.com;drwon@amc.seoul.kr
Young Jae Kim and Chang Jin Jung contributed equally as first authors.
Youngkyoung Lim and Chong Hyun Won contributed equally as
corresponding authors.
1
Department of Dermatology, Asan Medical Center, University of Ulsan
College of Medicine, 88 Olympic- ro 43 gil, Songpa-gu, Seoul, Korea
Full list of author information is available at the end of the article
Kim et al. Diagnostic Pathology (2022) 17:41
https://doi.org/10.1186/s13000-022-01218-3
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Background
It still remains a diagnostic challenge to distinguish be-
nign lesion from early malignancy in melanocytic lesions
of the nail unit, both clinically and histopathologically
[1,2]. Although non-invasive diagnostic tools including
the ABCDEF rulehad been proposed for early clinical
detection of subungual melanoma [3], still the biopsy
and histopathological evaluation is the gold standard in
distinguishing subungual melanoma in situ (MIS) from
benign subungual melanocytic proliferation (SMP) in-
cluding lentigo and melanocytic nevus [4]. Especially,
assessing melanocyte density along the dermoepidermal
junction of nail unit has been proposed to be a reliable
diagnostic tool to distinguish subungual melanoma in
situ from subungual benign melanocytic proliferation:
melanocyte density more than 30 cells per 1 mm is
highly suggestive of subungual MIS [5]. However, it is
occasionally difficult to histopathologically distinguish
one from another, as melanocyte density can differ sig-
nificantly in subungual MIS and benign SMP depending
on the skin type of the patient and the sampled area [1].
Immunohistochemistry (IHC) can be used to help in
the diagnostic dilemma of benign melanocytic lesion
versus melanoma in situ. However, HMB-45, highlight-
ing the maturation of melanocyte in benign melanocytic
nevus, may not be useful in the diagnosis of MIS where
the dermal invasion is absent [6]. Meanwhile, p16, serv-
ing as a tumor suppressor protein in the regulation of
cell cycle and senescence, has been suggested to be inac-
tivated or lost in melanoma [7]. Nevertheless, Chu et al.
[1] found that IHC staining for p16 could not distinguish
subungual lentigo from subungual MIS.
Cyclin D1, a protein encoded by CCND1 gene, is one of
the key components of physiologic regulation of cell cycle.
Cyclin D1 regarded as oncogenic protein to promote cell
proliferation has been reported to be upregulated in vari-
ous malignancies including melanoma [8]. Ramirez et al.
[9] suggested higher level of cyclin D1 expression in pri-
mary melanoma compared with melanocytic nevus. Also,
Preferentially expressed Antigen in Melanoma (PRAME),
a tumor-associated antigen isolated by autologous T cells
in a melanoma patient, was reported to be overexpressed
in malignant melanomas rather than benign melanocytic
lesions [10]. Lezcano et al. [11] found that over 88% of
non-spindle cell primary cutaneous melanoma showed
diffuse positivity for PRAME while 86% of melanocytic
nevus were negative for PRAME.
However, IHC staining for cyclin D1 and PRAME has
not been thoroughly investigated in melanocytic lesions of
nail unit. The prevalence of subungual melanoma in Asian
population is quite higher than Western population; sub-
ungual melanoma has been reported to comprise about
1018% of cutaneous melanoma in Asian population [12,
13]. Relatively poor prognosis, distinct clinical features,
and diverse genetic mutation of subungual melanoma [14
16], may indicate differences in the biology of subungual
melanoma compared with other cutaneous melanoma.
Herein, we assessed the ability of promising two
markers, cyclin D1 and PRAME, to distinguish subun-
gual MIS from benign SMP, both clinically presenting as
melanonychia, in a retrospective study.
Methods
Patient selection
This retrospective study, approved by the Institutional
Review Board (IRB) of Asan Medical Center (IRB No.
2020 1102), included cases of benign SMP including
lentigo and nevi, and subungual MIS, confirmed by bi-
opsy at Asan Medical Center from January 2016 to De-
cember 2020. Cases of melanocytic activation without
proliferation and melanoma where dermal invasion was
identified were excluded.
Variables of interest
Demographic and clinical data were investigated through
reviewing electronic medical record (EMR) of Asan
Medical Center, including sex, age at diagnosis, age of
onset, duration of disease, location of the lesion, width
of melanonychia, color of melanonychia, and presence of
nail dystrophy or periungual pigmentation including
Hutchinsons sign and pseudo-Hutchinsons sign.
Histopathologic data including melanocyte density,
confluency, pagetoid melanocytosis, presence of inflam-
matory cell infiltration or melanophage, cytologic atypia
of melanocytes, and distribution of melanin pigment
were investigated through reviewing the slides by two
dermatopathologists (YJK, CJJ) with agreement. Melano-
cyte density was measured as the number of intraepithe-
lial melanocytes over 1 mm dermoepidermal junction of
the nail matrix. As more than 30 cells per millimeter
was reported to suggestive of melanoma in situ [5], we
analyzed the slides according to whether melanocyte
density was over 30 cells per millimeter or not. Cytologic
atypia defined as nuclear enlargement, hyperchromatism,
or prominent nucleoli was graded as follows: absence,
mild, moderate, and severe.
Immunohistochemical analysis
Skin tissues obtained for routine diagnostic pathologic
examinations were used for IHC studies of the anti-
CYCLIN D1 (1:100, Mouse monoclonal, clone SP4, cata-
log No.CELL MARQUE, CELL MARQUE, Rocklin,Cali-
fornia, USA), anti-PRAME (1:1000, Rabbit polyclonal,
catalog No.ab219650, ABCAM, Cambridge, UK). Forma-
lin fixed, paraffin-embedded tissue sections were immu-
nohistochemically stained for expression of anti-
CYCLIN D1 and PRAME using a BenchMark XT auto-
matic immunostaining device (Ventana Medical Systems,
Kim et al. Diagnostic Pathology (2022) 17:41 Page 2 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Tucson, AZ, USA) with ultraView Universal AP Red De-
tection Kit (Ventana Medical Systems, Tucson, AZ,
USA) according to the manufacturers instructions.
Cyclin D1 and PRAME expression was assessed in
both benign SMP and subungual MIS by counting pro-
portion of melanocytes with nuclear positivity under
200x magnification, which was statistically analyzed to
determine cutoff value regarding sensitivities and speci-
ficities, using Youden index (specificity + sensitivity 1).
Statistical analysis
Chi-squared test and Fishers exact test were used to com-
pare the categorical variables of clinicopathologic features
of subungual benign melanocytic proliferation and subun-
gual melanoma in situ. Mann-Whitney U test was used
for the continuous variables of clinicopathologic features.
Sensitivities and specificities for PRAME were calculated
to determine cutoff value regarding discriminatory power
assessed by the area under the receiver operating charac-
teristic curve (AUC), using MedCalc (version 20.0, Med-
Calc Software Ltd, Ostend, Belgium). All analyses except
for were performed using SPSS (version 23.0, IBM Corp,
Armonk, NY). In this study, the p-value of 0.05 was con-
sidered statistically significant.
Results
A total of 14 patients and 13 patients were diagnosed
with benign SMP and subungual MIS, respectively, at
Asan Medical Center from January 2016 to December
2020 (Supplementary Appendix 1). Of 14 cases of benign
SMP, 8 cases were diagnosed with subungual lentigo
while the others were subungual melanocytic nevus. The
demographic characteristics are summarized in Table 1.
The cohort of benign SMP included 7 males and 7 fe-
males with a mean age of 30.71 years (range, 766
years). The cohort of subungual MIS included 7 males
Table 1 Clinical features of subungual benign melanocytic proliferation and subungual melanoma in situ
Features Subungual benign melanocytic
proliferation (n= 14), n (%)
Subungual Melanoma
in situ (n= 13), n (%)
p-value
Sex 0.842
Male 7 (50) 7 (53.8)
Female 7 (50) 6 (46.2)
Age, years 0.061
Range 7-66 6-74
Mean ± SD 30.71 ± 19.83 44.92 ± 17.73
Onset age, years 0.048
a
Range 4-56 5-64
Mean ± SD 25.71 ± 15.97 39.46 ± 17.16
Prediagnosis duration, months 0.756
Range 8-240 6-180
Mean ± SD 59.21 ± 67.27 66.62 ± 64.12
Location 0.385
Finger 12 (85.7) 9 (69.2)
Toe 2 (14.3) 4 (30.8)
Width, mm 0.017
a
Range 1.00-13.00 1.50-15.00
Mean ± SD 3.39 ± 2.90 7.81 ± 4.87
Background pigmentation 1.000
Yes 11 (78.6) 11 (84.6)
No 3 (21.4) 2 (15.4)
Nail dystrophy 0.596
Yes 0 (0.0) 2 (15.4)
No 14 (100.0) 11 (84.6)
Periungual pigmentation 0.568
Yes 6 (42.9) 7 (53.8)
No 8 (57.1) 6 (46.2)
a
Statistically significant
Kim et al. Diagnostic Pathology (2022) 17:41 Page 3 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
and 6 females with a mean age of 44.92 years (range, 6
74 years). The patients with subungual MIS seemed to
be older than the patients with benign SMP, but the dif-
ference was not statistically significant (p= 0.061).
Characteristics of subungual benign melanocytic
proliferation and subungual melanoma in situ
The clinical features of benign SMP and subungual MIS
are summarized in Table 1. The patients with benign
SMP were more likely to have melanonychia at younger
age (mean ± SD, 25.71 ± 15.9) than the patients with sub-
ungual MIS (mean ± SD, 39.46 ± 17.16) (p= 0.048). The
mean duration from the onset of the skin lesion to diag-
nosis of benign SMP was 59.21 months (range, 8-240
months); the mean prediagnosis duration of subungual
MIS was 66.62 months (range, 6-180 months). The fin-
gernail was involved in 12 patients with benign SMP
(85.7%) and 9 patients with subungual MIS (69.2%),
while toenail was involved in 2 patients with benign
SMP (14.3%) and 4 patients with subungual MIS
(30.8%). The width of melanonychia was significantly
thinner in benign SMP (mean ± SD, 3.39 ± 2.90 mm)
than subungual MIS (mean ± SD, 7.81 ± 4.87 mm) (p=
0.017). Colors of melanonychia striata were tan, brown,
or black, with background pigmentation in 11 out of 14
patients with benign SMP (78.6%) and 11 out of 13 pa-
tients with subungual MIS (84.6%). There was no patient
with benign SMP showing nail dystrophy at the involved
nail. Periungual pigmentation on proximal nail fold or
hyponychium suggestive of Hutchinsons sign or
pseudo-Hutchinsons sign was observed in 6 patients
with benign SMP (42.9%). When it comes to subungual
MIS, nail dystrophy and periungual pigmentation was
found in 2 patients (15.4%) and 7 patients (53.8%) re-
spectively, with no significant difference compared with
benign SMP.
The histopathological features of benign SMP and sub-
ungual MIS are showed in Table 2. Melanocytic density
more than 30 cells per 1 mm stretch of subungual der-
moepidermal junction was not statistically different be-
tween subungual MIS and benign SMP (p= 0.182). Focal
confluency was identified significantly less in benign
SMP than subungual MIS (p< 0.001); 5 of 14 (35.7%)
cases showed focal confluency, while at least focal con-
fluency was found in all cases of subungual MIS. The
patients with benign SMP showed significantly less page-
toid melanocytosis (6 out of 14 patients) than subungual
MIS (12 out of 13) (p= 0.006). Inflammatory cell infiltra-
tion was found in 5 of 14 patients with benign SMP
(35.7%) and 5 of 13 patients with subungual MIS
(38.5%), respectively. Compared with subungual MIS, cy-
tologic atypia of benign SMP was significantly milder
(p< 0.001); 12 out of 14 patients with benign SMP
(85.7%) showed absent or mild cytologic atypia, while 10
out of 13 patients with subungual MIS (76.9%) showed
moderate to severe atypia. In benign SMP cases, mela-
nophage was found in 8 cases (57.1%), and melanin pig-
ment limited to basilar area was identified in 4 cases
(28.6%). In subungual MIS cases, melanophage was
found in 9 cases (69.2%), and melanin pigment in entire
epidermis was found in 9 cases (69.2%). More specific-
ally, out of 4 benign SMP showing melanocytic density >
30 cells/mm, 2 cases were lentigines and 2 cases were
nevi. All 5 benign SMP with confluency were nevi, 5 out
of the 6 benign SMP cases with pagetoid melanocytosis
Table 2 Histopathological features of subungual benign
melanocytic proliferation and subungual melanoma in situ
Features Subungual benign
melanocytic
proliferation
(n= 14), n (%)
Subungual
Melanoma in
situ (n= 13),
n (%)
p-value
Melanocyte density 0.182
30 cells/mm 10 (71.4) 6 (46.2)
> 30 cells/mm 4 (28.6) 7 (53.8)
Confluency < 0.001*
Yes 5 (35.7) 13 (100.0)
No 9 (64.3) 0 (0.0)
Pagetoid melanocytosis 0.006*
Yes 6 (42.9) 12 (92.3)
No 8 (57.1) 1 (7.7)
Inflammation 0.883
Yes 5 (35.7) 5 (38.5)
No 9 (64.3) 8 (61.5)
Atypia < 0.001*
No 6 (42.9) 0 (0.0)
Mild 6 (42.9) 3 (23.1)
Moderate 2 (14.3) 5 (38.5)
Severe 0 (0.0) 5 (38.5)
Melanophage 0.516
Yes 8 (57.1) 9 (69.2)
No 6 (42.9) 4 (30.8)
Melanin pigment 1.000
Basilar 4 (28.6) 4 (30.8)
Entire 10 (71.4) 9 (69.2)
cyclin D1 1.000
Positive 4 (28.6) 3 (23.1)
Negative 7 (71.4) 9 (66.9)
PRAME <0.001
a
Positive 1 (7.1) 10 (76.9)
Negative 13 (92.9) 3 (23.1)
Abbreviations: PRAME PReferentially expressed Antigen in MElanoma
a
Statistically significant
Kim et al. Diagnostic Pathology (2022) 17:41 Page 4 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
were lentigines, and 1 case was nevus. Also, out of 8 be-
nign SMP with atypia, 5 lentigines and 1 nevus showed
mild atypia, and 2 nevi showed moderate atypia.
The results of IHC staining are summarized in Table 3.
When it comes to benign SMP, four cases (28.6%)
showed 20% nuclear immunostaining for cyclin D1,
while 11 cases (71.4%) exhibited > 70% nuclear immuno-
staining for cyclin D1. 13 cases (92.9%) exhibited totally
negative staining for PRAME, while 1 case (7.1%)
showed 20% nuclear immunostaining for PRAME
(Fig. 1). In terms of subungual MIS, eight cases (61.5%)
showed 20% nuclear immunostaining for cyclin D1,
while 5 cases (38.5%) exhibited > 60% nuclear immuno-
staining for cyclin D1. 3 cases (23.1%) were totally nega-
tive for PRAME, while 10 cases (76.9%) exhibited > 50%
nuclear immunostaining for PRAME (Fig. 2).
Sensitivity and specificity of cyclin D1 and PRAME
Using the cutoff of 92.5%, with > 92.5% nuclear immu-
nostaining for cyclin D1 as a positive test for subungual
MIS, the sensitivity, specificity, positive predictive value
(PPV), and negative predictive value (NPV) of cyclin D1
to distinguish subungual MIS from benign SMP were
23.1%, 85.7%, 21.6%, and 91.7%, respectively. At this cut-
off, cyclin D1 showed poor overall discrimination be-
tween benign SMP and subungual MIS (AUC = 0.527,
95% CI = 0.3280.721) (Fig. 3). There was no significant
differences in the positivity of cyclin D1 with cutoff of
92.5% between two groups (p= 1.000) (Table 2).
Using the cutoff of 10%, with > 10% nuclear immuno-
staining for PRAME as a positive test for subungual
MIS, the sensitivity, specificity, PPV, and NPV of
PRAME for distinguishing subungual MIS from benign
SMP were 76.9%, 92.9%, 71.6%, and 99.8%, respectively.
At this cutoff, PRAME exhibited good overall discrimin-
ation between benign SMP and subungual MIS (AUC =
0.849, 95% CI = 0.6590.957) (Fig. 3), which distin-
guished two groups significantly better than cyclin D1
(p= 0.013). PRAME was significantly more expressed in
subungual MIS than benign SMP (p< 0.001) (Table 2).
Discussion
Distinguishing subungual melanoma from non-nail ap-
paratus acral melanoma is clinically important due to its
distinct clinical courses including high recurrence rate
and short progression-free survival [14,15]. Also, it has
been reported that subungual melanoma harbors more
distinct genomic alterations including CARD11,ARID2,
ARID1A,ARID1B,PTPRB, and PTPRK genes, compared
with acral melanoma [17].
Cyclin D1 in coordination with their catalytic partners
CDK4 and CDK6, contributes to promoting cell cycle
progression through transition from G1 to S phase [18].
Cyclin D1 upregulation with amplification of CCND1
has been documented in various malignancies including
breast, lung, colon, and oral cancers [19]. Meanwhile,
the expression rate of cyclin D1 in cutaneous melanoma
compared with benign melanocytic nevus has been dis-
cordantly reported [9,20,21]. When it comes to acral
melanoma, cyclin D1 has been reported to be overex-
pressed, resulting in constitutively activated MAPK sig-
naling pathway without NRAS or BRAF mutations [22
24]. In this regard, we had expected cyclin D1 IHC stain-
ing would be an effective discriminator of benign SMP
from subungual MIS.
However, cyclin D1 IHC staining seemed not to be re-
liable in distinguishing benign SMP from subungual
MIS, in this study. Positive nuclear immunostaining for
cyclin D1 was found in 4 out of 14 (28.6%) patients with
benign SMP and 3 out of 13 (23.1%) patients with sub-
ungual MIS using cutoff of 92.5% which was determined
Table 3 Immunohistochemistry staining of subungual benign
melanocytic proliferation and subungual melanoma in situ
Subungual benign
melanocytic
proliferation
(n= 14), n (%)
Subungual
Melanoma in
situ
(n= 13), n (%)
cyclin D1 nuclear
immunostaining
0% 2 (14.3) 2 (15.4)
>010% 0 (0.0) 2 (15.4)
>1020% 2 (14.3) 4 (30.8)
>2030% 0 (0.0) 0 (0.0)
>3040% 0 (0.0) 0 (0.0)
>4050% 0 (0.0) 0 (0.0)
>5060% 0 (0.0) 0 (0.0)
>6070% 0 (0.0) 1 (7.7)
>7080% 3 (21.4) 0 (0.0)
>8090% 3 (21.4) 1 (7.7)
>90100% 4 (28.6) 3 (23.1)
PRAME nuclear
immunostaining
0% 13 (92.9) 3 (23.1)
>010% 0 (0.0) 0 (0.0)
>1020% 1 (7.1) 0 (0.0)
>2030% 0 (0.0) 0 (0.0)
>3040% 0 (0.0) 0 (0.0)
>4050% 0 (0.0) 0 (0.0)
>5060% 0 (0.0) 3 (23.1)
>6070% 0 (0.0) 0 (0.0)
>7080% 0 (0.0) 1 (7.7)
>8090% 0 (0.0) 2 (15.4)
>90100% 0 (0.0) 4 (30.8)
Abbreviations: PRAME PReferentially expressed Antigen in MElanoma
Kim et al. Diagnostic Pathology (2022) 17:41 Page 5 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
regarding sensitivities and specificities using Youden
index, with poor sensitivity of 23.1%. The lack of diag-
nostic value of cyclin D1 overexpression in these lesions
may be due to the differences in the type of antibody
used, the positive cell count system, and cutoff point for
positivity [8]. Also, it is important to note that cyclin D1
overexpression does not always represent amplification
of CCND1; loss of cyclin D1 IHC staining does not al-
ways represent loss of function of CCND1, vice versa.
Epigenetic regulation including DNA methylation at
cytosine and histone acetylation can cause alteration in
mRNA and protein expression [25]. Therefore, further
genetic tests including fluorescent in situ hybridization
(FISH) for CCND1 may be needed for determining true
CCND1 amplification to discriminate between benign
SMP and subungual MIS [22].
PRAME gene is a member of cancer testis antigen
(CTA) gene family encoding a membrane-bound protein
recognized by T lymphocytes, causing autologous cyto-
toxic T cell-mediated immune response [26]. Except for
some distinct tissues including testis, ovary, placenta, ad-
renals, and endometrium, PRAME is not detected in
healthy human tissues [10]. Overexpression of PRAME
was found to inhibit retinoic acid (RA) mediated cell dif-
ferentiation, cell growth arrest, and apoptosis, contribut-
ing to tumorigenesis via inhibiting RA receptor signaling
[27]. PRAME has been reported to be overexpressed in a
variety of malignancies including malignant melanoma,
showing an utility in distinguishing between benign and
malignant lesions [28]. Although little has been studied
about the diagnostic utility of PRAME in subungual mel-
anocytic lesions, a recently published paper has validated
the usefulness of PRAME expression in differentiating
between melanoma and other nail unit melanocytic le-
sions [29]. In the paper, subungual melanomas were all
positive in PRAME IHC, and benign melanocytic lesions
of nail unit were all negative. However, out of the 25
melanoma cases, 20 cases were invasive melanoma,
while only 5 cases were MIS. Our paper provides add-
itional insight from current literature focusing on MIS,
which is more difficult to distinguish from benign
lesions.
In this study, we demonstrated that PRAME IHC
staining was a relia4ble discriminator of benign SMP
from subungual MIS. Positive nuclear immunostaining
for PRAME was found in 1 out of 14 (7.1%) patients
Fig. 1 Representative clinical morphology, photomicrographs of H&E staining, and IHC staining for cyclin D1and PRAME of selected subungual
benign melanocytic proliferation. One 7-year-old patient presenting with (A) 3.5 mm-wide melanonychia showed (B) melanocyte proliferation
showing mild atypia without confluency or pagetoid spread (200x magnification, H&E). (C) While cyclin D1 IHC showed over 70% nuclear
immunostaining (200x magnification), (D) PRAME IHC exhibited total negativity (200x magnification), (E) Sox-10 IHC (200x magnification)
Kim et al. Diagnostic Pathology (2022) 17:41 Page 6 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
with benign SMP and 10 out of 13 (76.9%) patients with
subungual MIS using cutoff of 10%, showing modest
sensitivity of 76.9% and good specificity of 92.9%. Cutoff
(10%) for positivity of PRAME in this study is quite dif-
ferent from previously reported cutoff values ranging
from 50 to 75% [7,10,28]. Differences in cutoff values
among studies may be due to divergences in IHC stain-
ing methodology and inter-observer variability in IHC
assessment [28]. Also, the type of melanocytic lesions in-
cluded in the studies might affect the differences in cut-
off value for positivity of PRAME. Unlike previous
studies, we assessed the expression of PRAME using
only subungual melanocytic lesions, known to have dif-
ferent genomic alterations with lower mutation burden
compared with other cutaneous melanomas [23,30].
Also, small sample size of this study might have influ-
enced the difference in cutoff value. Therefore, add-
itional studies of PRAME IHC in a large cohort of
melanocytic lesions with different subtypes are needed
to determine whether cutoff value for PRAME positivity
should differ according to the subtype of melanocytic le-
sions, or not.
Compared with cytogenetic studies including FISH,
IHC has several advantages including more rapid turn-
around time, lower cost, and higher accessibility. How-
ever, PRAME IHC can exhibit false positive and false
negative results, confusing the correct diagnosis. Lez-
cano et al. [11] reported that diffuse nuclear immunore-
activity for PRAME was found in 13.6% of cutaneous
melanocytic nevus. Also, Shyam et al. [28] demonstrated
focal immunopositivity of PRAME from 5 to 10% in
atypical but benign non-spitzoid melanocytic prolifera-
tions. In this study, 1 out of 14 (7.1%) patients with be-
nign SMP exhibited PRAME nuclear immunostaining
ranging from 10 to 20%. The significance of focal
PRAME positivity in benign melanocytic lesions is still
Fig. 2 Representative clinical morphology, photomicrographs of H&E staining, and IHC staining for cyclin D1 and PRAME of selected subunugal
melanoma in situ. One 44-year-old patient (A) 2 mm-wide melanonychia showed (B) atypical melanocyte proliferation with confluency and
pagetoid spread (200x magnification, H&E). Both (C) cyclin D1 and (D) PRAME IHC showed over 90% nuclear immunostaining (200x magnification,
respectively), (E) Sox-10 IHC (200x magnification)
Kim et al. Diagnostic Pathology (2022) 17:41 Page 7 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
unclear, which necessitate further studies to determine
the potential risk of malignant transformation related to
focal PRAME positivity. Additional cytogenetic and mo-
lecular tests can help avoiding overdiagnosis in the cases
with focal PRAME positivity [10].
Also, it has been reported that primary cutaneous
melanoma could be completely negative for PRAME
immunostaining [10]. In this study, 3 out of 13 (23.1%)
patients showed completely negative PRAME IHC.
Histopathological analysis revealed there was no mela-
nophage adjacent to cutaneous melanoma in these pa-
tients. Melanophage found in cutaneous melanoma is
indicative of immune responses, predicting a relatively
good prognosis for patients, possibly through tumor re-
gression due to phagocytosis of melanoma cells [31]. As
PRAME gene encodes a membrane-bound protein rec-
ognized by T lymphocytes causing autologous cytotoxic
T cell-mediated immune response [26], it is possible
that lack of PRAME expression may lead to decreased
immune response and reduced melanophages. While
PRAME was found to be related with metastasis in
uveal melanoma [32], little has been reported about the
prognostic value of PRAME expression in cutaneous
melanoma. Further studies are needed to determine the
prognostic value of PRAME expression in cutaneous
melanoma, regarding the role of PRAME in the rela-
tionship between immune response and oncogenesis.
It is important to keep in mind that IHC should be
used in conjunction with clinical findings and histo-
logical analysis to make a final diagnosis. Clinically, we
found that the patients with subungual MIS tended to
be older and have wider lesions than the patients with
benign SMP, with statistical significance. We also dem-
onstrated that the patients with subungual MIS showed
significantly more confluency, pagetoid melanocytosis,
and severe atypia than the patients with benign SMP.
Combining these clinical and histopathological features
with PRAME IHC may significantly increase diagnostic
power to distinguish benign SMP from subungual MIS.
This study has several limitations. First, this study was
a retrospective study with relatively small sample size.
Small sample size limited the usage of multivariate logis-
tic regression analysis to develop a scoring system for
the diagnosis of subungual melanoma in situ using
PRAME expression. Second, this study was a single-
center study confined to Korean patients. As the differ-
ence in the prevalence rate of subungual melanoma be-
tween the Asian group and other races including
Fig. 3 Receiver Operating Characteristic (ROC) curve for discriminating subungual MIS from benign SMP based on the expression levels of Cyclin
D1 and PRAME. Using the cutoff of 92.5%, with > 92.5% nuclear immunostaining for cyclin D1 as a positive test for subungual MIS, cyclin D1
showed poor overall discrimination between benign SMP and subungual MIS (AUC = 0.527, 95% CI = 0.3280.721). Using the cutoff of 10%, with
> 10% nuclear immunostaining for PRAME as a positive test for subungual MIS, PRAME exhibited good overall discrimination between benign
SMP and subungual MIS (AUC = 0.849, 95% CI = 0.6590.957)
Kim et al. Diagnostic Pathology (2022) 17:41 Page 8 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Western group is prominent enough to suppose differ-
ence in the biology of subungual melanoma in each
group. Therefore, cyclin D1 and PRAME expression in
melanocytic lesions of nail unit should be studied in
other races including Western group. Also, this study
evaluated no cytogenetic or molecular studies to com-
pare with PRAME IHC in the diagnosis of subungual
MIS.
Conclusions
This study suggests that PRAME IHC staining as a reli-
able discriminator in distinguishing subungual MIS from
benign SMP. We also demonstrated PRAME expression
should be interpreted in the context of histopathologic
features. Further studies using larger cohort and ancil-
lary studies including cytogenetic studies are needed to
confirm the diagnostic utility of cyclin D1 and PRAME
expression in the diagnosis of subungual MIS.
Abbreviations
IHC: Immunohistochemistry; MIS: Melanoma in situ; SMP: Subungual
melanocytic proliferation; PRAME: Preferentially expressed Antigen in
Melanoma; PPV: Positive predictive value; NPV: Negative predictive value;
CTA: Cancer testis antigen; RA: Retinoic acid
Supplementary Information
The online version contains supplementary material available at https://doi.
org/10.1186/s13000-022-01218-3.
Additional file 1: Supplementary Appendix 1. Clinical and
histopathological data for all cases included.
Acknowledgements
We would like to thank all patients who participated in the study. We would
like to thank the National Research Foundation of Korea for providing
research funding.
Authors' contributions
YJK and CJJ designed the study, collected the clinical, histopathological data,
analyzed the data, and wrote the manuscript. CSP performed
immunohistochemical study. All authors commented on previous versions of
the manuscript. All authors read and approved the final manuscript.
Funding
This research was supported by the National Research Foundation of Korea
(NRF) grant funded by the Korean government (MSIT). (No.
2020R1F1A1074674).
Availability of data and materials
The data that support the findings of this study are available from the
corresponding author upon reasonable request.
Declarations
Ethics approval and consent to participate
This retrospective study was approved by the Institutional Review Board (IRB)
of Asan Medical Center (IRB No. 2020 1102).
Consent for publication
All the patients involved in this study gave their written informed consent
for publication of their case details.
Competing interests
The authors declare that they have no competing interests.
Author details
1
Department of Dermatology, Asan Medical Center, University of Ulsan
College of Medicine, 88 Olympic- ro 43 gil, Songpa-gu, Seoul, Korea.
2
Department of Pathology, Asan Medical Center, University of Ulsan College
of Medicine, 88 Olympic- ro 43 gil, Songpa-gu, Seoul, Korea.
3
Present
address: Department of Dermatology, Seoul National University Hospital, 101,
Daehak ro, Jongno gu, Seoul, Korea.
Received: 9 November 2021 Accepted: 5 April 2022
References
1. Chu A, Andre J, Rich P, Leachman S, Thompson CT. Immunohistochemical
characterization of benign activation of junctional melanocytes and
melanoma in situ of the nail unit. J Cutan Pathol. 2019;46:47983.
2. Di Chiacchio N, Hirata SH, Enokihara MY, Michalany NS, Fabbrocini G, Tosti
A. Dermatologistsaccuracy in early diagnosis of melanoma of the nail
matrix. Arch Dermatol. 2010;146:3827.
3. Levit EK, Kagen MH, Scher RK, Grossman M, Altman E. The ABC rule for
clinical detection of subungual melanoma. J Am Acad Dermatol. 2000;42:
26974.
4. Lee JH, Park JH, Lee JH, Lee DY. Early detection of subungual melanoma In
situ: proposal of ABCD strategy in clinical practice based on case series. Ann
Dermatol. 2018;30:3640.
5. Amin B, Nehal KS, Jungbluth AA, Zaidi B, Brady MS, Coit DC, et al. Histologic
distinction between subungual lentigo and melanoma. Am J Surg Pathol.
2008;32:83543.
6. Prieto VG, Shea CR. Immunohistochemistry of melanocytic proliferations.
Arch Pathol Lab Med. 2011;135:8539.
7. See SHC, Finkelman BS, Yeldandi AV. The diagnostic utility of PRAME and
p16 in distinguishing nodal nevi from nodal metastatic melanoma. Pathol
Res Pract. 2020;216:153105.
8. Gonzalez-Ruiz L, Gonzalez-Moles MA, Gonzalez-Ruiz I, Ruiz-Avila I, Ayen A,
Ramos-Garcia P. An update on the implications of cyclin D1 in melanomas.
Pigment Cell Melanoma Res. 2020;33:788805.
9. Ramirez JA, Guitart J, Rao MS, Diaz LK. Cyclin D1 expression in melanocytic
lesions of the skin. Ann Diagn Pathol. 2005;9:1858.
10. Lezcano C, Jungbluth AA, Busam KJ. Comparison of immunohistochemistry
for PRAME with cytogenetic test results in the evaluation of challenging
melanocytic tumors. Am J Surg Pathol. 2020;44:893900.
11. Lezcano C, Jungbluth AA, Nehal KS, Hollmann TJ, Busam KJ. PRAME
expression in melanocytic tumors. Am J Surg Pathol. 2018;42:145665.
12. Park SW, Jang KT, Lee JH, Park JH, Kwon GY, Mun GH, et al. Scattered
atypical melanocytes with hyperchromatic nuclei in the nail matrix:
diagnostic clue for early subungual melanoma in situ. J Cutan Pathol. 2016;
43:4152.
13. Saida T, Ohshima Y. Clinical and histopathologic characteristics of early
lesions of subungual malignant melanoma. Cancer. 1989;63:55660.
14. Miura S, Jimbow K. Clinical characteristics of subungual melanomas in
Japan: case report and a questionnaire survey of 108 cases. J Dermatol.
1985;12:393402.
15. Moon HR, Kang HJ, Won CH, Chang SE, Lee MW, Choi JH, et al.
Heterogeneous spectrum of acral melanoma: a clinicoprognostic study of
213 acral melanomas according to tumor site. J Am Acad Dermatol. 2018;
78:17982.
16. Newell F, Wilmott JS, Johansson PA, Nones K, Addala V, Mukhopadhyay P,
et al. Whole-genome sequencing of acral melanoma reveals genomic
complexity and diversity. Nat Commun. 2020;11:5259.
17. Lee M, Yoon J, Chung YJ, Lee SY, Choi JY, Shin OR, et al. Whole-exome
sequencing reveals differences between nail apparatus melanoma and acral
melanoma. J Am Acad Dermatol. 2018;79:55961.
18. Malumbres M, Barbacid M. Cell cycle, CDKs and cancer: a changing
paradigm. Nat Rev Cancer. 2009;9:15366.
19. Alao JP. The regulation of cyclin D1 degradation: roles in cancer development
and the potential for therapeutic invention. Mol Cancer. 2007;6:24.
20. Alekseenko A, Wojas-Pelc A, Lis GJ, Furgal-Borzych A, Surowka G, Litwin JA.
Cyclin D1 and D3 expression in melanocytic skin lesions. Arch Dermatol Res.
2010;302:54550.
21. Georgieva J, Sinha P, Schadendorf D. Expression of cyclins and cyclin
dependent kinases in human benign and malignant melanocytic lesions. J
Clin Pathol. 2001;54:22935.
Kim et al. Diagnostic Pathology (2022) 17:41 Page 9 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
22. Cho-Vega JH, Cao T, Ledon J, Moller M, Avisar E, Elgart G, et al. Diagnostic
application of cyclin D1 fluorescent in situ hybridization for histologically
undetermined early lesions of acral melanoma in situ: a case series. Ann
Diagn Pathol. 2021;50:151681.
23. Ibrahim ZA, Narihan MZ, Ojep DN, Soosay AE, Pan KL. Cyclin D1 expression
in acral melanoma: a case control study in Sarawak. Malays J Pathol. 2012;
34:8995.
24. Takata M, Goto Y, Ichii N, Yamaura M, Murata H, Koga H, et al. Constitutive
activation of the mitogen-activated protein kinase signaling pathway in
acral melanomas. J Invest Dermatol. 2005;125:31822.
25. Guo ZY, Hao XH, Tan FF, Pei X, Shang LM, Jiang XL, et al. The elements of
human cyclin D1 promoter and regulation involved. Clin Epigenetics. 2011;
2:6376.
26. Xu Y, Zou R, Wang J, Wang ZW, Zhu X. The role of the cancer testis antigen
PRAME in tumorigenesis and immunotherapy in human cancer. Cell Prolif.
2020;53:e12770.
27. Epping MT, Wang L, Edel MJ, Carlee L, Hernandez M, Bernards R. The
human tumor antigen PRAME is a dominant repressor of retinoic acid
receptor signaling. Cell. 2005;122:83547.
28. Raghavan SS, Wang JY, Kwok S, Rieger KE, Novoa RA, Brown RA. PRAME
expression in melanocytic proliferations with intermediate histopathologic
or spitzoid features. J Cutan Pathol. 2020;47:112331.
29. Krajisnik A, Gharavi NM, Faries MB, Balzer BL, Frishberg DP, Martelli M, et al.
Immunohistochemistry for Preferentially Expressed Antigen in Melanoma in
the Differential Diagnosis of Melanocytic Lesions of the Nail Apparatus. Am
J Dermatopathol. 2022; https://doi.org/10.1097/dad.0000000000002143.
30. Furney SJ, Turajlic S, Stamp G, Thomas JM, Hayes A, Strauss D, et al. The
mutational burden of acral melanoma revealed by whole-genome
sequencing and comparative analysis. Pigment Cell Melanoma Res. 2014;27:
8358.
31. Handerson T, Berger A, Harigopol M, Rimm D, Nishigori C, Ueda M, et al.
Melanophages reside in hypermelanotic, aberrantly glycosylated tumor
areas and predict improved outcome in primary cutaneous malignant
melanoma. J Cutan Pathol. 2007;34:67986.
32. Field MG, Decatur CL, Kurtenbach S, Gezgin G, van der Velden PA, Jager MJ,
et al. PRAME as an independent biomarker for metastasis in Uveal
melanoma. Clin Cancer Res. 2016;22:123442.
PublishersNote
Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.
Kim et al. Diagnostic Pathology (2022) 17:41 Page 10 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
1.
2.
3.
4.
5.
6.
Terms and Conditions
Springer Nature journal content, brought to you courtesy of Springer Nature Customer Service Center GmbH (“Springer Nature”).
Springer Nature supports a reasonable amount of sharing of research papers by authors, subscribers and authorised users (“Users”), for small-
scale personal, non-commercial use provided that all copyright, trade and service marks and other proprietary notices are maintained. By
accessing, sharing, receiving or otherwise using the Springer Nature journal content you agree to these terms of use (“Terms”). For these
purposes, Springer Nature considers academic use (by researchers and students) to be non-commercial.
These Terms are supplementary and will apply in addition to any applicable website terms and conditions, a relevant site licence or a personal
subscription. These Terms will prevail over any conflict or ambiguity with regards to the relevant terms, a site licence or a personal subscription
(to the extent of the conflict or ambiguity only). For Creative Commons-licensed articles, the terms of the Creative Commons license used will
apply.
We collect and use personal data to provide access to the Springer Nature journal content. We may also use these personal data internally within
ResearchGate and Springer Nature and as agreed share it, in an anonymised way, for purposes of tracking, analysis and reporting. We will not
otherwise disclose your personal data outside the ResearchGate or the Springer Nature group of companies unless we have your permission as
detailed in the Privacy Policy.
While Users may use the Springer Nature journal content for small scale, personal non-commercial use, it is important to note that Users may
not:
use such content for the purpose of providing other users with access on a regular or large scale basis or as a means to circumvent access
control;
use such content where to do so would be considered a criminal or statutory offence in any jurisdiction, or gives rise to civil liability, or is
otherwise unlawful;
falsely or misleadingly imply or suggest endorsement, approval , sponsorship, or association unless explicitly agreed to by Springer Nature in
writing;
use bots or other automated methods to access the content or redirect messages
override any security feature or exclusionary protocol; or
share the content in order to create substitute for Springer Nature products or services or a systematic database of Springer Nature journal
content.
In line with the restriction against commercial use, Springer Nature does not permit the creation of a product or service that creates revenue,
royalties, rent or income from our content or its inclusion as part of a paid for service or for other commercial gain. Springer Nature journal
content cannot be used for inter-library loans and librarians may not upload Springer Nature journal content on a large scale into their, or any
other, institutional repository.
These terms of use are reviewed regularly and may be amended at any time. Springer Nature is not obligated to publish any information or
content on this website and may remove it or features or functionality at our sole discretion, at any time with or without notice. Springer Nature
may revoke this licence to you at any time and remove access to any copies of the Springer Nature journal content which have been saved.
To the fullest extent permitted by law, Springer Nature makes no warranties, representations or guarantees to Users, either express or implied
with respect to the Springer nature journal content and all parties disclaim and waive any implied warranties or warranties imposed by law,
including merchantability or fitness for any particular purpose.
Please note that these rights do not automatically extend to content, data or other material published by Springer Nature that may be licensed
from third parties.
If you would like to use or distribute our Springer Nature journal content to a wider audience or on a regular basis or in any other manner not
expressly permitted by these Terms, please contact Springer Nature at
onlineservice@springernature.com
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
To increase understanding of the genomic landscape of acral melanoma, a rare form of melanoma occurring on palms, soles or nail beds, whole genome sequencing of 87 tumors with matching transcriptome sequencing for 63 tumors was performed. Here we report that mutational signature analysis reveals a subset of tumors, mostly subungual, with an ultraviolet radiation signature. Significantly mutated genes are BRAF, NRAS, NF1, NOTCH2, PTEN and TYRP1. Mutations and amplification of KIT are also common. Structural rearrangement and copy number signatures show that whole genome duplication, aneuploidy and complex rearrangements are common. Complex rearrangements occur recurrently and are associated with amplification of TERT, CDK4, MDM2, CCND1, PAK1 and GAB2, indicating potential therapeutic options.
Article
Full-text available
Preferentially expressed antigen in melanoma (PRAME), which belongs to the cancer/testis antigen (CTA) gene family, plays a pivotal role in multiple cellular processes and immunotherapy response in human cancers. PRAME is highly expressed in different types of cancers and is involved in cell proliferation, apoptosis, differentiation and metastasis as well as the outcomes of patients with cancer. In this review article, we discuss the potential roles and physiological functions of PRAME in various types of cancers. Moreover, this review highlights immunotherapeutic strategies that target PRAME in human malignancies. Therefore, the modulation of PRAME might be useful for the treatment of patients with cancer.
Article
Nail unit melanocytic lesions present a unique set of diagnostic challenges because of the unfamiliarity with clinical assessment and the lack of experience with histologic examination. Because the first surgical specimen received in the pathology laboratory is typically small, sometimes suboptimal biopsy, the distinction between melanoma and its histologic mimics can be difficult. For this reason, there has been a continued interest in the development of ancillary markers that may assist in the differential diagnosis of nail unit melanocytic lesions. Upregulation of preferentially expressed antigen in melanoma (PRAME) has been reported to be a common event in melanomas, and PRAME immunohistochemistry has been shown to be helpful in evaluating various melanocytic neoplasms. In this study, we evaluated PRAME protein expression in a series of nail unit melanocytic lesions. Twenty-five nail unit melanomas (including small biopsy and amputation specimens) and 32 control benign melanocytic lesions were retrospectively retrieved. Nuclear PRAME staining was scored as percentage and intensity labeling. All melanoma cases showed the nuclear expression of PRAME, which was usually diffuse and strong. In specimens where the neoplastic cells are limited in number, the staining was restricted to the tumor cells, corresponding to the initial H&E impression. All control cases were negative for PRAME expression. PRAME expression is helpful in distinguishing between melanomas and other nail unit melanocytic lesions. This antibody also proved to be diagnostically valuable in detecting melanoma cells in small specimens with minimal disease.
Article
Context.—Histologic analysis allows accurate classification of most melanocytic lesions as benign or malignant. Only in a minority of lesions is it necessary to use other techniques as an aid in the diagnosis. Among them, most authors recommend immunohistochemistry. Objective.—To describe how to apply immunohistochemistry to particular differential diagnoses and the potential pitfalls. Data Sources.—Personal experience and review of literature. Conclusions.—here is no single marker, or combination thereof, that establishes an unequivocal diagnosis of melanoma or nevus. Thus it is necessary to carefully analyze the pattern of expression (patchy versus diffuse) and localization (maturation) in the context of morphologic standard features.
Article
Histologically undetermined early acral melanoma in situ (HUAMIS) is rare but a diagnostic challenge, being clinically and dermoscopically MIS (late onset, a large size (>7 mm), parallel ridges pattern) but microscopically without recognizable cytological atypia. Cyclin D1 (CCND1) gene amplification is a genetic aberration occurring in the early radial growth phase of AMs and could thus help determine malignancy for this disease. We determine the value of CCND1 amplification by FISH as a diagnostic marker for HUAMIS. CCND1 amplification was examined in paraffin-embedded skin biopsies and excisions using a dual-probes fluorescence in situ hybridization (FISH) (11q13 and CEP11). One FISH-negative case 6 was additionally examined by Mypath Melanoma (qRT-PCR). Seventeen cases (12 dysplastic nevi, 3 AMIS, and 2 invasive AM) were served as negative controls for FISH. All six patients (4 females and 2 males) were Hispanic. Pigment lesions were on the left plantar foot (4), right third finger palm (1), and right thumb subungual (1). All cases showed similar clinical and dermoscopical characteristics, including late onset (50 to 74 years old), long duration (from 2 to 15 years), large-sized pigments (from 16 to 40 mm), and a parallel ridge pattern. Junctional melanocytes with no or minimal atypia from five cases showed CCND1 amplifications. Four of 5 cases were received 1st or/and 2nd wide excisions, which demonstrated foci of histologically overt MIS. One FISH-negative case 6 demonstrated “likely malignancy” scores (>2) by Mypath Melanoma (qRT-PCR). None of negative controls showed the amplification. We propose here a simple CCND1 FISH is a practical diagnostic test to determine the malignancy of the very early progression phase of AM preceding histopathologically defined MIS. Cases presented here could be an indolent subtype of AMIS characterized by carrying a long latent radial growth phase without vertical growth, mimicking lentigo maligna.
Article
BACKGROUND PRAME (PReferentially expressed Antigen in MElanoma) has shown utility in distinguishing melanoma from benign melanocytic lesions, but knowledge of its expression pattern in intermediate melanocytic and spitzoid proliferations is limited. METHODS Immunohistochemical expression of PRAME was examined in 112 melanocytic proliferations with intermediate histopathologic or spitzoid features. RESULTS Any intensity of PRAME staining in at least 60% of lesional melanocytes was determined as the best threshold for diffuse staining in this cohort. Nearly all non‐spitzoid melanomas (23/24; 95.8%) demonstrated diffuse PRAME expression. PRAME was completely negative in 95.6% (43/45) of mitotically‐active nevi, traumatized nevi, nevi with persistent/recurrent features, and dysplastic nevi. Most Spitz nevi (15/20) and atypical Spitz tumors (10/13) entirely lacked PRAME expression. One Spitz nevus, one atypical Spitz tumor, and one case of spitzoid melanoma (1/2) demonstrated diffuse PRAME expression. CONCLUSIONS Although diffuse PRAME expression is generally limited to malignant melanoma, benign Spitz nevi and atypical Spitz tumors can infrequently express diffuse PRAME. PRAME immunohistochemistry can be useful in the evaluation of atypical melanocytic proliferations with intermediate histopathologic features but should be interpreted with caution in the setting of spitzoid neoplasms. This article is protected by copyright. All rights reserved.
Article
The status of the sentinel lymph node is the strongest predictor of recurrence in patients with malignant melanoma, making accurate distinction between nodal metastases and nodal nevi of paramount importance. We explored the utility of p16 and PRAME in differentiating nodal nevi from metastatic melanoma by immunohistochemistry. We searched our institutional database for cases of nodal nevi and nodal metastatic melanoma. p16 and PRAME expression were assessed with immunolabeling quantified by extent of nuclear positivity (0-25%, >25%-50%, >50%-75% and >75%). Sensitivities and specificities were calculated, and discrimination assessed using the area under the receiver operating characteristic curve (AUC). Forty-nine cases out of 51 nevi and 56/56 melanoma cases had lesional tissue present for p16, while 44/51 nevi and 54/56 melanoma cases had lesional tissue present for PRAME. 43 nodal nevi (88%) had >50% nuclear staining for p16, while none had >50% staining for PRAME. More than half (55%) of melanoma cases had complete loss of nuclear staining for p16, while majority (94%) had >50% nuclear staining for PRAME. Using a cut-off value of 50%, higher PRAME expression had a sensitivity and specificity of 94% and 100%, respectively, while lower p16 expression had a sensitivity and specificity of 66% and 88%, respectively, for detecting metastatic melanoma. PRAME showed significantly better discrimination (AUC = 0.97, 95% CI 0.94-1.00) than p16 (AUC = 0.77, 95% CI 0.68-0.86) for differentiating nodal nevi from nodal melanoma (P < 0.001). Our findings suggest that PRAME is more accurate than p16 in discriminating between the two entities, with excellent sensitivity and specificity.
Article
PRAME (PReferentially expressed Antigen in MElanoma) is a melanoma-associated antigen. Although diffuse immunoreactivity for PRAME is found in most primary cutaneous melanomas, melanocytic nevi express PRAME usually only in a subpopulation of tumor cells or not at all. Hence, testing for PRAME expression has the potential to provide useful information for the assessment for diagnostically ambiguous melanocytic neoplasms. Many of the latter tumors are currently studied by cytogenetic methods for ancillary evidence in support of or against a diagnosis of melanoma. In this study we analyzed 110 diagnostically problematic melanocytic tumors comparing results for PRAME immunohistochemistry (IHC) with those from fluorescence in situ hybridization and/or single nucleotide polymorphism-array, and each with the final diagnostic interpretation. In 90% of cases there was concordance between PRAME IHC and cytogenetic tests results, and in 92.7% concordance between PRAME IHC and the final diagnosis. The high concordance between PRAME IHC and cytogenetic test results as well as the final diagnosis supports the use of PRAME IHC as an ancillary test in the evaluation of ambiguous primary cutaneous melanocytic neoplasms, especially given its practical advantage of lower cost and faster turnaround over cytogenetic or gene expression studies. However, our results indicate that PRAME IHC and cytogenetic tests for melanocytic tumors are not entirely interchangeable and on occasion each type of test may yield false-negative or false-positive results.
Article
Cyclin D1 is a protein encoded by the CCND1 gene, located on 11q13 chromosome, which is a key component of the physiological regulation of the cell cycle. CCND1/cyclin D1 is upregulated in several types of human tumors including melanoma and is currently classified as an oncogene that promotes uncontrolled cell proliferation. Despite the demonstrated importance of CCND1/cyclin D1 as a central oncogene in several types of human tumors, its knowledge in melanoma is still limited. This review examines data published on upregulation of the CCND1 gene and cyclin D1 protein in the melanoma setting, focusing on the pathways and molecular mechanisms involved in the activation of the gene and on the clinical and therapeutic implications.