A 22-year-old woman undergoes laparotomy for a right ovarian mass. The histology shows a tumor composed of cells resembling primitive germ cells with large nuclei and vesicular chromatin arranged in lobules separated by fibrous septa infiltrated by lymphocytes. What is the MOST likely diagnosis and its cell of origin?

• A Granulosa cell tumor; granulosa cells of sex cord
• B Endodermal sinus tumor; endodermal cells
• C Dysgerminoma; primordial germ cells ✓
• D Immature teratoma; totipotent germ cells

Explanation

Dysgerminoma arises from primordial germ cells and is the most common malignant germ cell tumor of the ovary. Histologically it is identical to testicular seminoma: large cells with vesicular nuclei, prominent nucleoli, in lobules separated by fibrous septa with lymphocytic infiltration. It is highly radiosensitive and chemosensitive (BEP regimen). AFP is not elevated; LDH and beta-hCG (in syncytiotrophoblastic cells) can be elevated as tumor markers.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.