CM Choi, et al
S82 Ann Dermatol
Table 1. Summary of reported cases of eccrine porocarcinoma in Korean literature
Author Sex Age Duration Site Size Metastasis Treatment
Kim et al.
F 86 10 years Right thigh 5.0×4.0 cm Regional LN Excision＋radiation
ung et al.
F 72 5 years Left buttock 4.5×4.5 cm − Excision
Lee et al.
M 69 30 years Back 2 cm − None
Han et al.
F 71 5 years Scalp 4.0×3.8 cm − Excision
Yoon et al.
M 57 3 years Right thumb 1.7 cm − Excision
Kim et al.
F 37 4 years Ant.helix of right ear 1.0×1.0 cm − Excision
Lee et al.
F 84 1.25 year Left eyelid 0.8×0.8 cm − Excision
Shin et al.
F825∼6 years Scalp 2.0×2.0 cm − Mohs surgery
Oh et al.
M 55 7 years Left sole 1.0×1.0 cm − Excision
Oh et al.
M 54 2 years Back 1.0×1.0 cm − Excision
Park et al.
M 75 3 months Suprapubic area 2.0×2.0 cm − Excision
Choi et al.
F 71 4 years Right palm 3.5×2.5 cm − Excision
Present case M 44 7 months Right scrotum 6.0×7.0 cm ＋ Chemotherapy
According to Shaw et al.
, all 27 cases of EPC arose from
a benign eccrine poroma (BEP); however, Robson et al.
reported occurrence of EPC in only 18% of cases of BEP.
In our view, skin manifestations of our patient developed
de novo because there was no preexisting lesion on the
scrotum as well as on the pelvic area. In addition, EPC that
arises from BEP usually shows very slow progression. This
patient was relatively young and his disease showed an
aggressive clinical course; the tumor developed primarily
on the scrotum and showed rapid metastasis to multiple
The histopathologic features of EPC are broad. Malignant
cells usually have large and hyperchromatic nuclei.
Nuclear atypia with frequent mitoses and necrosis are
characteristic. Cords and nests of polygonal tumor cells
penetrate to the adjacent dermis or extend into subcu-
taneous tissue. Histopathologically, metastatic adenocar-
cinoma, trabecular carcinoma, and Merkel cell carcinoma
should be included in the differential diagnosis. Distin-
guishing EPC from metastatic adenocarcinoma, and espe-
cially adenocarcinoma of a breast or lung origin, can be
difficult. However, most metastatic adenocarcinomas are
positive for EMA and CEA stains. Furthermore, a positive
reaction with CEA may be most helpful in differentiating
between primary and secondary lesions
. In the present
case, the negative reaction with CEA, the connection bet-
ween the epidermis and tumor, and the absence of
glandular structures are evidence for exclusion of the
diagnosis of metastatic adenocarcinoma. Trabecular carci-
noma and Merkel cell carcinoma also show findings com-
parable with EPC. Hyperchromatic, large, and irregular
nuclei arranged in cord or trabecular patterns are common
features of EPC and trabecular carcinoma; however, the
latter shows nuclear molding. On immunoperoxidase
studies, EMA and CK-7 are positive, and S-100 protein and
CK-20 are negative in EPC. CEA is negative in most EPC;
however, it can be positive in tumors containing well-
. However, trabecular carcinoma or Merkel
cell carcinomas express neuron-specific enolase (NSE) and
CK-20, and they do not express CK-7
. This present case
showed positivity for EMA and CK-7 and negativity for
S-100 protein, CK-20, and CEA. The negative result for
CEA might be due to the paucity of ductal structures in
Snow and Reizner
suggested local recurrence and
regional metastatic rates of approximately 20% and devel-
opment of distant metastases in 12% of cases. Similarly,
Robson et al.
observed that 11% of patients had metas-
tasis to distant organs; these patients have a high mortality
rate (64% in the series). They suggested that the prognosis
of EPC depends mainly on mitoses (more than 14 per high
power field), lympho-vascular invasion, and a tumor
depth of more than 7 mm. The present case was positive
for all of these poor prognostic factors, and this might
have induced the fatal clinical course.
We experienced a rather novel case of EPC on an uncom-
mon site and the patient presented with rapid multiple
metastases. Most EPCs are localized and a few of them are
metastatic. Therefore, it is essential to consider the possi-
bility of metastases of primary EPC in the process of
diagnostic evaluation of patients who are found to be
normal on a physical examination.
1. Pinkus H, Mehregan AH. Epidermotropic eccrine carcinoma:
a case combinig features of eccrine poroma and paget’s
dermatosis. Arch Dermatol 1963;88:597-606.
2. Robson A, Greene J, Ansari N, Kim B, Seed PT, McKee PH,
et al. Eccrine porocarcinoma (malignant eccrine poroma): a
clinicopathologic study of 69 cases. Am J Surg Pathol 2001;
3. Kim JS, Ro YS, Park CK. A case of malignant eccrine poroma.