[An adenomatoid tumor of the uterus]

Three adenomatoid tumors of the uterus were examined. These tumors arising in the uterus are often regarded as incidental findings at operation, and are sometimes not well recognized at the time of diagnosis. They are small nodular lesions in the wall of the myometrium. Microscopically they presented with four distinctive histologic types, and immunohistochemically gave positive staining for keratin and for the mesothelial marker. The immunohistochemical results support the theories of histogenesis of the adenomatoid tumor as a type of benign mesothelioma.