Uterine perivascular epithelioid cell tumour

Uterine perivascular epithelioid cell tumour (PEComa) is a rare disease and its biological behaviour remains unclear. This paper describes the clinical, histological and immunohistochemical features of three cases of uterine PEComa to add to our limited knowledge of the biological characteristics of these tumours. Histologically, the tumours were characterised by an epithelioid arrangement of tumour cells with abundant clear to eosinophilic, pale, granular cytoplasm. Immunohistochemically, the tumours were uniformly positive for HMB45, desmin and progesterone receptor; they were uniformly negative for h-caldesmon, α-smooth muscle actin, CD34, epithelial membrane antigen (EMA) and oestrogen receptor (ER). Review of the literature suggests that the size of the primary tumour (> 5 cm in diameter) and high mitotic rates are two important indicators of recurrence. Treatment options are limited though new mTOR inhibitors show some promise in early reports.