An 18-year-old woman has a solid ovarian mass. Serum lactate dehydrogenase is markedly elevated while CA 125, AFP and beta-hCG are normal. Histology shows uniform large cells with clear glycogen-rich cytoplasm arranged in sheets and nests, separated by fibrous septa infiltrated with mature lymphocytes. Immunohistochemistry will most likely show positivity for:

• A SALL4 and glypican-3 only, with OCT4 negativity
• B Inhibin and calretinin
• C CD30 and cytokeratin
• D OCT4 and PLAP ✓

Explanation

Dysgerminoma, the female counterpart of testicular seminoma, occurs in young women, produces elevated LDH, and shows sheets of uniform cells with clear cytoplasm and lymphocytic septa. Its immunoprofile mirrors seminoma: nuclear OCT4 and membranous PLAP positivity, often with CD117. Option B corresponds to sex cord-stromal tumours such as granulosa cell tumour. CD30 positivity indicates embryonal carcinoma, and SALL4 with OCT4 negativity plus elevated AFP would suggest yolk sac tumour, whose histology differs.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.