A 17-year-old girl with primary amenorrhoea has a 46,XY karyotype and bilateral streak gonads removed prophylactically. Histology shows nests of large primordial-type germ cells surrounded by smaller sex cord cells forming eosinophilic rounded spaces filled with basement membrane material. No mitoses or lymphovascular invasion are seen. What is this lesion called?

• A Juvenile granulosa cell tumour
• B Pure dysgerminoma
• C Mixed germ cell-sex cord stromal tumour, unclassified
• D Gonadoblastoma ✓

Explanation

Gonadoblastoma is an in situ neoplasm composed of germ cells and sex cord stromal cells arranged in nests with eosinophilic basement membrane deposits, occurring almost exclusively in dysgenetic gonads carrying Y chromosomal material such as Swyer syndrome. It is itself benign but frequently gives rise to invasive dysgerminoma, hence prophylactic gonadectomy. Pure dysgerminoma lacks the organised sex cord component, and juvenile granulosa tumour presents with precocious puberty rather than streak gonads.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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