Cystadenofibromas of the ovary with epithelial atypia.

Epithelial atypia is rarely encountered in ovarian cystadenofibromas. Ten examples are reported with cytological features identical to serous tumors with low malignant potential. In two neoplasms the epithelium resembled an atypical endometrial hyperplasia, and one of these had squamous metaplasia. These two neoplasms probably qualify as endometrioid tumors of low malignant potential. None of the 10 patients had recurrence following excision of their neoplasm, and no similar patients have been encountered with neoplasms in more advanced stages. Even though aggressive behavior has not yet been established, the histologic features suggest a low degree of malignant potential and long-term follow-up of patients is warranted. Cystadenofibromas iwth epithelial atypia probably have less malignant potential than serous tumors of low malignant potential possessing the same epithelial characteristics because cystadenofibromas with atypia have less epithelial surface area and the epithelium is enveloped by connective tissue more than it is in serous tumors of low malignant potential.