Fine needle aspiration diagnosis of bilateral dysgerminoma with syncytiotrophoblastic giant cells.

Dysgerminoma accounts for only 1-3% of ovarian cancers and about 30-40% of all ovarian germ cell malignant tumors. Literature states that about 2% of nonpregnant patients with dysgerminomas present with elevated serum or urine levels of human chorionic gonadotropin (hCG). Here, we report a 34 year-old multiparous woman presenting with an abdominal lump, ascites, and abdominal pain with elevated urinary and serum hCG levels. An abdominal ultrasound showed bilateral ovarian mass. An ultrasound-guided, transabdominal fine needle aspiration revealed dysgerminoma with syncytiotrophoblastic giant cells. Bilateral oophorectomy was done and the diagnosis was confirmed on histopathology.

Introduction

Dysgerminoma is defined by the WHO as an ovarian tumor composed of a monotonous proliferation of primitive germ cells associated with connective tissue septa containing varying amounts of lymphocytes and macrophages. The usually well-encapsulated tumor masses are apparently unilateral in 90% of cases. Macroscopic involvement of the contralateral ovary is apparent in 10% of cases and in another 10% of cases, occult foci of dysgerminoma can be detected by biopsy. Occasionally, syncytiotrophoblastic differentiation is noted.[1]

Case Report

A 34 year-old multiparous, nonpregnant woman presented with an abdominal lump, ascites, and abdominal pain. An abdominal ultrasound showed bilateral ovarian mass with solid as well as bilateral hypo-echoic areas. The left ovarian mass measured 15 × 13 cm and the right one measured around 7 × 7 cm. An ultrasound-guided, transabdominal fine needle aspiration cytology (FNAC) was done from both the ovarian masses.

The hypercellular smears consisted chiefly of dispersed as well as cohesive clusters of cells with well defined cell borders, vacuolated cytoplasm, and round, vesicular nuclei with prominent nucleoli. The most interesting finding was the presence of quite a few number of syncytiotrophoblastic giant cells [Figure 1]. A diagnosis of dysgerminoma with syncytiotrophoblastic giant cell was given and the patient was advised to undergo a β-hCG titre examination.

Figure 1

(a) FNAC smear showing syncytiotrophoblastic giant cells(arrow) along with dysgerminoma cells (H and E, ×100). (b) FNAC smear showing the syncytiotrophoblastic giant cell (H and E, ×400)

Following the FNAC report, a urinary qualitative β-hCG titre and a serum β hCG titre were done and both yielded positive results, with the serum β hCG titre being 98,000 mIU/mL. Bilateral oophorectomy was done.

Gross examination showed a bilateral ovarian tumor; the left one measuring 15 × 15 cm and the right one being around 8 cm in diameter. The outer surface was congested and the cut section showed mainly cystic areas along with solid areas. Multiple sections were given from representative areas.

The sections from the tumor showed the presence of fibrous septa dividing the nests of cells with well defined borders, clear cytoplasm, and vesicular nuclei with prominent nucleoli. The fibrous septa contained an abundance of lymphocytes. Quite a few multinucleated giant cells reminiscent of syncytiotrophoblasts were seen to be present, being distributed diffusely. No component of any other germ cell tumor was present in the multiple sections studied; large areas of necrosis were present [Figure 2]. A histopathological diagnosis of dysgerminoma with syncytiotrophoblastic giant cells was given. At the six months’ follow-up, the patient was relieved of tumor signs and symptoms and the serum β hCG titre was reported to be normal.

Figure 2

(a) Syncytiotrophoblastic giant cells in a background of dysgerminoma cells in tissue section (H and E, ×400). (b) Tissue section showing fibrous septae dividing tumor cells in nest like fashion (arrow) (H and E; ×100)

Discussion

Dysgerminoma accounts for only 1–3% of ovarian cancers and about 30–40% of all ovarian germ cell malignant tumors. Pure ovarian dysgerminomas with associated elevation of hCG are rare (around 2%) and their optimum management is unclear.[2]

A raised β hCG titre may result in hormonal manifestations that may mimic an ectopic pregnancy or hydatiform mole. FNAC of ovarian neoplasms is a relatively less frequented area. However, a study by Hemlatha et al,[3] of US-guided FNAC of 105 cases of ovarian neoplasms demonstrated a diagnostic accuracy of 89.75% with a false negative rate of 4.76%. Here, we report a unique case of an FNAC diagnosis of bilateral dysgerminoma of the ovary with syncytiotrophoblastic giant cells associated with elevated β hCG in a nonpregnant woman whose diagnosis was later confirmed by histopathology.

Zaloudek et al,[4] had described six cases of dysgerminomas with syncytiotropoblastic giant cells diagnosed on histopathology. Kim et al,[2] described a single case of pure dysgerminoma with syncytiotrophoblastic giant cell secreting β-HCG. Similar reports have been published by Kapp et al,[5] and Davidson.[6] But there is a dearth of reports of FNAC diagnosis of a pure dysgerminoma with syncytiotrophoblastic giant cells and elevated β hCG titres. Serial estimation of β hCG titre forms a valuable part of the follow-up of these patients. Our patient showed normal serum β-HCG titre at the six months’ follow–up.