Sclerosing stromal tumour--a rare ovarian benign neoplasm: description of three cases.

Sclerosing stromal tumour is a rare benign usually unilateral ovarian tumour. We present three cases of this neoplasm in young females, including one bilateral case. All tumours were composed of cellular areas forming pseudolobular patterns, as well as vascular, fibrous, and myxoid areas. The characteristic feature of tumours was cellular heterogenity. All tumours revealed negative immunostaining for cytokeratin, and intense positive immunostaining for vimentin, and smooth muscle actin. Immunostaining for desmin and progesterone receptors was weakly positive.