A 19-year-old woman undergoes laparotomy for a solid ovarian mass. Histology shows sheets of large cells with clear cytoplasm, central nuclei, and intervening lymphocytic stroma. Serum LDH is markedly elevated. What is the most likely diagnosis and its serum marker?

• A Yolk sac tumor — AFP
• B Dysgerminoma — LDH and β-hCG ✓
• C Immature teratoma — AFP
• D Granulosa cell tumor — Inhibin B

Explanation

Dysgerminoma is the most common malignant germ cell tumor of the ovary in young women, histologically identical to testicular seminoma. It shows large uniform cells with clear glycogen-rich cytoplasm and a lymphocytic stroma. LDH (particularly isoenzyme 1) is the primary serum marker; a minority also produce β-hCG from syncytiotrophoblastic giant cells. AFP elevation points to yolk sac tumor or immature teratoma.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.