Ovary, Juvenile granulosa cell tumour

Juvenile granulosa cell tumour is a sex-cord gonadal stromal tumour that often arises in the ovaries of girls but can also occur very rarely in the testes of boys. Sections demonstrate tumour with obliteration of the normal ovarian architecture. The tumour is composed of sheets of cells and variably sized nodules and follicular formation. The tumour cells range from epithelioid to spindled in morphology with abundant eosinophilic cytoplasm. The nuclei are round to ovoid and mildly pleomorphic with finely dispersed chromatin and small nucleoli. Nuclear grooves are not a prominent finding. There are occasional mitoses. There is no surface involvement of the ovary. Immunohistochemical stains show positive staining of tumour cells for calretinin. There is patchy positive staining for inhibin-a and pan keratin to a lesser degree. EMA is negative.