Primary peritoneal mesodermal adenosarcoma: report of a case and review of the literature

BACKGROUND: Mesodermal (müllerian) adenosarcoma arising from the peritoneum is rare and is thought to arise from pluripotent mesothelial and mesenchymal cells of the pelvic cavity or from endometriotic deposits. CASE: A case of primary peritoneal mesodermal adenosarcoma arising from the omentum is described. A 50-year-old woman presented with sudden abdominal distension. Initial laparotomy revealed a 13-kg mass arising from the omentum, which was determined from frozen and paraffin sections to be serous cystadenofibroma. The tumor recurred within 10 months and weighed 18 kg at a second laparotomy. Histopathology and review of the original tumor established the correct diagnosis of mesodermal adenosarcoma. The patient died from disseminated disease 6 months later. CONCLUSION: Adenosarcomas are difficult to differentiate from adenofibromas or endometriosis histologically because of the presence of large areas of low cellularity and infrequent mitotic figures. In such cases, stromal nuclear atypia and periglandular stromal cuffing are features that are diagnostic of adenosarcoma.