Primary primitive neuroectodermal tumor of the ovary
, Wen-Chun Chang
, Kuan-Ting Kuo
, Bor-Ching Sheu
Department of Obstetrics and Gynecology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
Department of Pathology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
Centre for Optoelectronic Biomedicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
Accepted 27 August 2013
The most common neoplastic ovarian tumor in adolescence is
the germ cell tumor. About 58% of primary ovarian neoplasms are
germ cell tumors, and most are benign cystic teratomas . Ovarian
tumors composed of primitive neuroectodermal elements are
We report a case of an ovarian primitive neuroectodermal tumor
(PNET) treated with fertility-sparing staging surgery and adjuvant
chemotherapy, followed by six courses of chemotherapy.
A 16-year-old nulliparous girl presented with a pelvic mass
which she had palpated accidentally. The mass grew rapidly over 3
weeks. The patient had experienced intermittent abdominal
discomfort and irregular menstruation in recent months, but there
had been no bowel habit changes. She visited our clinic and her
tumor proﬁle was checked. A detailed sonographic examination
showed one huge, solid, 16.5 cm 9.2 cm pelvic tumor with
heterogenous echo complex contents including some cystic parts
and calciﬁcation, with a suspected ovarian origin (Fig. 1). Abdom-
inal and pelvic magnetic resonance imaging revealed a huge mass
lesion in the pelvic cavity, which showed low T1 signal intensity
and intermediate highT2 signal intensity, with some internal cystic
components and good enhancement (Fig. 2).The patient was then
referred to our oncology clinic, where tumor markers for suspected
malignancy revealed an elevated carbohydrate antigen (CA)-125
level (120.9 U/mL), with normal levels of lactate dehydrogenase,
carcinoembryonic antigen, CA-199, alpha-fetoprotein (AFP) and
beta-human chorionic gonadotropin. The patient denied a family
history of ovarian cancer and teratoma. She also denied symptoms
of neuroendocrine activity such as ﬂushing, diarrhea, abdominal
cramping, and palpitations.
An exploratory laparotomy revealed a huge left ovarian solid
tumor with an irregular border and central necrosis (Fig. 3). The
uterus, bilateral fallopian tubes, omentum, and peritoneal surface
were grossly normal. There was a moderate amount of ascites,
about 400 mL. In consideration of her fertility at this young age,
conservative staging surgery with a left salpingo-oophorectomy,
dissection of left side pelvic lymph nodes, and infracolic omental
excision was performed.
Immediate pathological frozen section revealed a spindle cell
tumor. A detailed microscopic pathological examination showed
the well-encapsulated ovarian tumor to be composed of grayish
tan, solid, ﬂeshy tissue with several small cysts with clear ﬂuid.
Marked necrosis was seen.
Microscopically, the tumor showed a high cellularity, composed
of small cells with hyperchromatic, round to oval nuclei and scanty
to small amounts of cytoplasm arranged in lobules separated by
ﬁbrovascular septa, patternless sheets incompletely divided by
ﬁbrovascular septa or a trabecular/cord-like pattern (Fig. 4). A
ﬁbrillary matrix was focally present. Mitotic activity (>10/10 HPF,
high power ﬁeld) and apoptosis were frequently seen and tumor
necrosis was evident. Immunohistochemically, the tumor was
relatively diffusely positive for synaptophysin and cluster of dif-
ferentiation (CD) 56, focally positive for chromogranin, S-100 and
glial ﬁbrillary acidic protein, with the latter two particularly pre-
dominant in the ﬁbrillary matrix area, but negative for cytokeratin
(AE1/AE3), CD99, and AFP. Based on the above ﬁndings, the tumor
resembled a PNET of the central nervous system with a medullo-
blastoma/neuroblastoma pattern. In addition, small areas of mature
teratoma composed of squamous epithelium, respiratory epithe-
lium, bone, cartilage, smooth muscle, adipose tissue, mature glial
tissue, and minor nondescript ducts were also present. Therefore, a
primitive ovarian neuroectodermal tumor in association with a
teratoma was considered.
The patient’s postoperative course was smooth and she was
discharged from the hospital after surgery. Under a diagnosis of left
ovarian PNET, Stage IC, adjuvant chemotherapy for epithelial
ovarian cancer was administered with the PT (carboplatin AUC: 6,
paclitaxel 175 mg/m
) protocol six times at 3-week intervals
without severe side effects, except for alopecia.
She was regularly followed for 13 months at our clinic without
evidence of recurrence, with regular menstrual cycles and a normal
*Corresponding author. Department of Obstetrics and Gynecology, National
Taiwan University Hospital, Number 7, Chung-Shan South Road, Taipei 100, Taiwan.
E-mail address: email@example.com (B.-C. Sheu).
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Taiwanese Journal of Obstetrics & Gynecology 53 (2014) 409e412
hormone proﬁle. The tumor makers including CA-125 were all
normal during regular monthly follow ups. Follow up with
ﬂuorodeoxyglucose-positron emission tomography 12 months af-
ter completion of chemotherapy also showed negative ﬁndings.
Primary neuroectodermal tumors are rare monophasic tera-
tomas composed of immature neuroectodermal tissue. The tumors
are separate from other types of teratomas and the incidence is
rare. These tumors are classiﬁed as ependymoma, astrocytoma, and
primitive neuroepithelial tumors such as medulloblastoma,
medulloepithelioma and neuroblastoma . PNETs are highly
cellular and composed of small cells with hyperchromatic, round to
oval nuclei and scanty cytoplasm. Lobules separated by ﬁbrovas-
cular septa are present with prominent areas of necrosis .
Based on previous reports, most primary PNETs occur in the
second to third decades of life, at a slightly younger age than the
well-differentiated form of neuroectodermal tumors. The age range
of patients in one study was 13 to 69 years . The prognosis is
generally poor with a high mortality rate.
Kleinman et al  reported 12 PNETcases in Stage IA to Stage III.
The duration of posttreatment follow-up ranged from 2 months to
9 years. All patients with Stage IA-IC disease received unilateral
salpingo-oophorectomy. Postoperative adjuvant chemotherapy
was administered in three of four patients with Stage I disease. No
patient had evidence of disease during follow-up. However, nearly
all patients (7 of 8) in Stage III died of disease at 2e20 months after
Because of the rarity of cases, there is no consensus about the
operative method or adjuvant therapies such as chemotherapy and
radiotherapy. One case report in 2004 described a patient with
PNET Stage IIIC with peritoneal carcinomatosis and extensive
lymphadenopathy who received fertility-sparing staging surgery
and adjuvant radiotherapyand chemotherapy with carboplatin and
paclitaxel. She died after 10 months due to septic shock .
The adjuvant chemotherapy regimen varies in reports (Table 1).
Some authors used the bleomycin, etoposide, and cisplatin (BEP)
regimen as in other germ cell tumors, and some used cisplatin,
Fig. 1. Ultrasonography shows a huge, solid, heterogeneous tumor in the pelvic cavity.
Fig. 2. Abdominal and pelvic magnetic resonance imaging reveals a huge mass lesion
with low T1 signal intensity. B ¼urinary bladder; R ¼rectum; V ¼vagina.
L.-H. Chu et al. / Taiwanese Journal of Obstetrics & Gynecology 53 (2014) 409e412410
etoposide, cyclophosphamide, and doxorubicin as a neuroblastoma
treatment protocol [5,6]. In our case, carboplatin and paclitaxel
were used, which followed the regimen for epithelial ovarian
cancer. Megadose chemotherapy followed by peripheral blood
progenitor cell rescue has been reported for metastatic disease .
New chemotherapy drugs and drug combinations are being
tested for the treatment of ovarian cancer. Drugs such as tra-
bectedin (Yondelis) and belotecan have shown promise in some
studies. However, we could ﬁnd no reports on the effects of these
two drugs on ovarian PNET because of the rarity of the disease.
In summary, ovarian PNET is a rare type of germ cell tumor.
The tumor should be differentiated from a wide variety of pri-
mary and metastatic ovarian tumors with similar clinical pic-
tures, and the diagnosis is usually conﬁrmed with pathology.
There is no consensus about the treatment strategy for ovarian
PNET due to the rarity of the disease, although surgery and
chemotherapy are commonly used clinically. More studies are
needed to evaluate the response and effectiveness of different
Fig. 3. Left ovarian tumor revealed during exploratory laparotomy (A) and the cut surface (B).
Fig. 4. The tumor shows lobules of small round cells separated by ﬁbrovascular septa
(hematoxylin &eosin stain; original magniﬁcation, 400).
Cases of primary primitive neuroectodermal tumors (PNET) of ovary mentioning chemotherapy regimens.
Reference Pathology Age (y) Stage Residual tumor after
Treatment Follow-up recurrence
et al, 2004 
PNET 25 IC Nil Surgery þCT
Left SO, pelvic ¶-aortic
VIP 6 (salvage CT)
3 y, NED þ, at lymphocyst
et al, 2010 
Neuroblastoma 17 IC Nil Surgery þCT
Bilateral SO, omentectomy
cisplatin þetoposide 7
6 y, NED
et al, 2012 
PNET 28 III Nil Surgery þCT
Left SO, cytoreduction,
18 mo, DOD þ, pelvis
Lawlor et al, 1997  Neuroblastoma 13 IIIC Diffuse peritoneal
Right SO þomentectomy
Cisplatin þetoposide þ
18 mo, NED
Kim et al, 2004  PNET 18 IIIC Diffuse peritoneal
Surgery þCT þRT
RSO, omentectomy, LN biopsy
10 mo, death
due to septic
et al, 2011 
Medulloblastoma 23 IIIC Diffuse peritoneal
Bilateral SO, omentectomy
6 y, NED
et al, 2007 
PNET 28 IV Lung, adrenal
Doxorubicin þactinomycin þ
13 mo, DOD þ
BEP ¼bleomycin, etoposide, cisplatin; CT ¼chemotherapy; DOD ¼died of disease; EFT ¼Ewing’s family of tumors; LN ¼lymph nodes; NED ¼no evidence of disease; RT ¼
radiotherapy; SO ¼salpingo-oophorectomy; VACA ¼vincristine, actinomycin, cyclophosphamide, doxorubicin; VIP ¼vinblastine, ifosfamide, cisplatin.
L.-H. Chu et al. / Taiwanese Journal of Obstetrics & Gynecology 53 (2014) 409e412 411
Conﬂicts of interest
The authors have no conﬂicts of interest relevant to this article.
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