Author
Information
Bakre Tejashree *, Patil Lalita
Y**, Gupta AS.
(* Second Year Resident, *** Professor.
Department of Obstetrics and Gynecology, ** Assistant
Professor, Department of Pathology; Seth
G.S. Medical
College and K.E.M
Hospital , Mumbai , India
Abstract
A 20 year old primigravida with 19 weeks of pregnancy came with pain in abdomen, dysuria and frequent urination. She was diagnosed as a case of Gastro Intestinal Stromal Tumor (GIST) of the descending colon on ultrasonography (USG). Magnetic resonance
imaging (MRI) & Doppler sonography diagnosed the mass as a sub-serosal fibroid of the uterus. During emergency lower segment cesarean section (LSCS) at term the ovarian origin of the mass was discovered.
Introduction
Dysgerminoma is the commonest malignant ovarian
germ cell tumor diagnosed in pregnancy.[1,2,3]
These tumors can however be misdiagnosed as sub-serosal fibroids
or tumors of the colon. At times modalities like Doppler and MRI can also lead to
misdiagnoses.[4] Such masses
are then diagnosed accidentally. Here we present a
case of left ovarian dysgerminoma misdiagnosed as fibroid during antenatal
period resulting in delay of her definitive treatment.
Case Report
A 20 year old primigravida with 19 weeks of gestation presented
with complaints of dull aching pain in left lumbar region and dysuria for 15
days. On examination her vital
parameters were stable, chest was clear, abdominally uterus was 20 weeks in size and relaxed. An 11 x 8 cm sized non tender mass separate from
uterus and hard in consistency was palpated in left lumbar region. On vaginal
examination a firm, non tender mass was felt high up in the left fornix. An ultrasound examination
revealed a 19 weeks size normal intrauterine fetus and a large hyperechoic,
well defined, highly vascular mass measuring 11cm x 8 cm x 8 cm in the left
lumbar region. USG differential diagnosis
was GIST of the descending colon or a left subserosal fibroid of the uterus. MRI of the
pelvis and abdomen was suggestive of a large subserosal or broad ligament
fibroid but possibility of GIST could not be ruled out. The patient was closely
followed by obstetrician and gastroenterologist. Rest of antenatal period was
unremarkable. The patient underwent an emergency LSCS under spinal anesthesia
at term in view of thick meconium stained liquor in latent stage of labor.
Intraoperatively, after birth of a term fetus a large lobulated mass, hard in
consistency, smooth surfaced, measuring 25 x 20 x 8 cm arising from the
left ovary and free from the bowel was seen.
A thick leash of blood vessels was seen extending from the base of the
mass to the left cornua of the uterus and into the mesosalpinx.
Figure 1. Large
left ovarian tumor with a thick leash of vessels during Cesarean section.
M: is the mass.
Arrow shows the thick leash of blood vessels in the mesoovarium.
The surgeon deferred the excision of the mass
due to its high vascularity and the thick leash of blood vessels seen in its
pedicle. Tumor
markers like LDH, AFP and β-HCG were sent, chest radiograph was obtained. Tumor
markers (LDH-2290 U/L and β -HCG – 26 mIU/L) were elevated. Exploratory
laparotomy was performed after puerperium. Peritoneal washings were sent for cytology. A left ovarian mass lobulated, bosselated 19 x15 x5 cm in size was
seen. A left salpingo-oophorectomy was done and the tumor
was sent for frozen section.Cut
surface was solid, greyish white, firm, fleshy, and bulging. Frozen section was suggestive of
a malignant ovarian tumor probably a mixed germ cell tumor.
Figure 2a. Left
large ovarian neoplasm. M is the mass; Black arrow is the vascular pedicle and
the green arrow shows the normal uterus.
Figure 2b. Gross:
Large, lobulated 19 x15 x5 cm, solid mass.
Figure 3. Cut surface:
Solid, greyish-white, fleshy with bulging cut surface.
Opposite ovary and uterus were inspected which were
grossly normal. Peritoneum of the cul de sac, liver, omentum, under surface of the diaphragm, colon,
bowel mesentery, spleen, bladder
peritoneum, pelvic and para aortic lymph nodes were evaluated and found to be
grossly normal. As the patient was young and desirous of further child bearing only unilateral
salpingo-oophorectomy was done. Peritoneal cytology showed presence of malignant cells (FIGO stage 1c).
Final histopathology report confirmed the tumor to be an ovarian dysgerminoma. The
patient was referred to an oncology center for adjuvant treatment.
Figure 4. H&E 40X:
Shows tumor cells are arranged in nests, sheets and cord separated by fibrous
septae. C are the tumor cells and S are the fibrous septae.
Figure 5. H&E 100X:
Shows stromal lymphocytic infiltration (L) and few mitotic figures were seen.
Figure 6. H&E
400X: Shows large round to polygonal cells with high N:C ratio, pleomorphic
hyperchromatic nuclei, thick nuclear membrane, prominent eosinophilic nucleoli
and moderate vacuolated cytoplasm.
Discussion
Dysgerminoma accounts for only 1-2% of all
malignant ovarian tumors. Dysgerminoma occurs mainly in children
and young women.[3] The average age is 22 years, and 90 percent of the patients are less
than 30 years of age. About 20 percent of malignant ovarian tumors detected during
pregnancy are dysgerminomas. Differential
diagnosis of
a pelvic mass in pregnancy include uterine leiomyomas, overdistended urinary bladder, ovarian neoplastic
cysts, GIST, impacted feces, large hydrosalpinx and retroperitoneal tumor.
[5]
This case is interesting as it posed
diagnostic challenges ranging from GIST to subserosal leiomyoma and finally
dysgerminoma. USG is the primary imaging modality.[6] However not only USG but also MRI misdiagnosed the
dysgerminoma as a fibroid uterus in our case.
MRI has around 98% sensitivity
for detecting ovarian origin of a mass.[4,7] However there have been reports of mistaking a
malignant ovarian tumor for pedunculated uterine fibroid with areas of cystic
degeneration as in our case.[4] Such adnexal masses are then
diagnosed for first time during LSCS.
Tumor markers elevated in a case of a dysgerminoma are most commonly LDH
and occasionally β-HCG, when the dysgerminoma has components of
syncytiotrophoblasts. Raised AFP is less common. Preoperative evaluation of all of the tumor markers is
advisable in patients with suspected germ cell tumor or dysgerminoma.[5] A MRI diagnosis of fibroid uterus misguided us and
so tumor markers were not studied in the antenatal period. Had these tumor
markers been done the diagnosis would have been established and the patient
could have been operated in the antenatal period itself, or along with LSCS. The tumor may
then have been staged as FIGO stage 1a. For patients with stage Ia dysgerminoma,
unilateral salpingo-oophorectomy conserving the uterus and opposite ovary is
accepted treatment in a young patient desirous of preserving her fertility. The
initial treatment of these patients is surgery, which includes unilateral
salpingo-oophorectomy. Frozen section is performed. Multiple biopsies from the
peritoneum, omentum, and contralateral ovary, and pre- and paraaortic lymph nodes
are taken and studied. Peritoneal washings are subjected for cytological
analysis.[8] The frozen section pathologic diagnosis in our case was mixed germ cell tumor as the pathologist studied only
representative section. In such cases it is best to
defer definitive surgery. Fortunately, the accuracy of frozen section diagnosis
of ovarian tumors is more than 90%.[9] Incompletely staged patients or those with
higher stage tumors (1c and above) should probably receive adjuvant
treatment like radiation therapy or chemotherapy. [10]
References
1.
Smith HO,
Berwick M, Verschraegen CF, Wiggins C, Lansing L, Muller CY, et al. Incidence
and survival rates for female malignant germ cell tumors. Obstet Gynecol.
2006;107(5):1075-85.
2.
Lee KH, Lee
IH, Kim BG, Nam JH, Kim WK, Kang SB, et al. Clinicopathologic characteristics
of malignant germ cell tumors in the ovaries of Korean women: a Korean
Gynecologic Oncology Group Study. Int Journal of Gynecol Cancer.
2009;19(1):84-7.
3.
Zaloudek C . Current
Issues Part Two ,Case 13 Dysgerminoma Available at: http://pathology.ucsf.edu/uploads/376/182_CZ%20Current%20Issues%202012%20Part%202.pdf
4.
Anwar S, Rehan
B, Hameed G MRI for the diagnosis of ultrasonographically indeterminate
pelvic masses- Journal of Pakistan Medical Association, 2014; February:
171-174.
5.
Michener C M, HuhW K. Available
at: http://emedicine.medscape.com/article/253701-overview/
6.
Munir S S, Misbah S And Dawood A D. The Evaluation Of Pelvic Mass.
Biomedica Vol.26, Jan. – Jun. 2010/Bio-14.
7.
Yoon K, Chang Y, Guisera L, et al. Ovarian dysgerminoma in pregnancy.
Korean J Obstet Gynecol 2011;54(4):218-222.
8.
Dark GG , Bower M, Newlands ES, Paradinas F, Rustin GJS. Surveillance Policy for Stage I Ovarian Germ Cell
Tumors. J Clin Oncol 1997;15, No 2:
620-624.
9.
Leiserowitz GS. Managing Ovarian Masses During Pregnancy: Obstet Gynecol
Survey 2006: 61, No 7:463-470.
10. Medical Protocol
Ovarian Germ Cell Tumour (Ogct) – Management Guidelines Protocol No:
ME-O1 (Version No: 1) http://www.mccn.nhs.uk/userfiles/documents/ Ovarian% 20
germ%20cell%20protocol%20(final%20version).pdf
Citation
Bakre T, Patil LY, Gupta
AS.