Benign and low grade variants of mixed mesodermal tumor (adenosarcoma) of the ovary and adnexal region

Abstract

Eleven examples of a rare group of neoplasms composed of both epithelial and mesenchymal components are reported. Ten arose from the ovary and one arose separately in the para-ovarian region. The neoplasms are distinctive in that the stroma is more cellular than that of adenofibromas, but the epithelial component is not malignant, as in carcinosarcoma and mixed mesodermal tumors, and the stroma is not sarcomatous in the low grade varieties. The 11 cases were highly variable in the cellularity and atypism of the stromal cells. The term, adenosarcoma, for these tumors is not acceptable because some were too low a grade to be regarded as sarcomas, and reports of the uterine counterpart disclose that some contain heterologous elements. For that reason, a term that will embrace the full spectrum of changes in the stroma—benign through sarcomatous—is needed. We propose that they be regarded as variants of mixed mesodermal tumor so that both the benign neoplasms and low grade sarcomas can be accommodated under one designation. Of the 11 cases, five lowest grade examples were all confined to the ovary and did not recur after surgical excision, but some of these were borderline in malignancy and probably would have progressed if untreated. Two of the 3 intermediate grade neoplasms extended beyond the ovary but were arrested by surgical excision. The 3 highest grade neoplasms were overtly sarcomatous. One of these extended beyond the ovary but was arrested by combination chemotherapy. The para-ovarian adenosarcoma (also high grade) metastasized and proved fatal.