An 18-year-old woman has a solid unilateral ovarian mass. Microscopy shows sheets of uniform round cells with central nuclei and cleared cytoplasm, divided into nests by fibrous septa infiltrated with mature lymphocytes. Which immunohistochemical profile is expected?

• A Inhibin positive, calretinin positive, cytokeratin negative
• B Cytokeratin 7 and PAX8 positive, PLAP negative
• C OCT4 and CD30 positive, AFP negative
• D OCT4 and PLAP positive, CD30 negative ✓

Explanation

The histology describes dysgerminoma, the ovarian counterpart of testicular seminoma. It is composed of primitive germ cells that express OCT4 (POU5F1), SALL4, PLAP, and B2-40, while CD30 is characteristically negative, which separates it from embryonal carcinoma (OCT4 and CD30 both positive). Inhibin and calretinin mark sex cord stromal tumors such as granulosa cell tumor. Cytokeratin 7 and PAX8 positivity would fit surface epithelial carcinoma. Dysgerminomas are radiosensitive and carry an excellent prognosis when confined to the ovary.

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.