Ovarian adenocarcinoma of mesonephric type

Ovarian adenocarcinoma of mesonephric type is a well-differentiated carcinoma composed of clear or hobnail-type cells resembling renal carcinoma. Forty cases were studied. Although there is no proof of origin from mesonephric remnants in or near the ovary, these neoplasms are virtually identical to carcinomas that arise from mesonephric rests elsewhere, as in the cervix. It is apparent that neoplasms with this pattern occasionally arise in endometriosis of the ovary and are associated with pelvic endometriosis in 25% of instances. Origin from endometriosis is uncommon, however; none of the 40 examples in this study arose from endometriosis, and there are relatively few examples in the literature. Therefore, the most common origin is from pluripotential ovarian epithelium, and this simply reflects the capacity of the ovary to produce neoplasms resembling those arising in other organs in the abdominal cavity. Factors related to survival included whether the neoplasms were essentially unilocular (favorable) or essentially multilocular or solid (unfavorable). Predominance of papillary patterns and clear cells in the neoplasm was relatively favorable, as compared with predominance of hobnail cells or tubular patterns. Of 28 patients who had neoplasms visibly confined to the ovary at initial operation, 61% were living and well at last contact. Because of the relatively favorable prognosis, a specific designation is recommended.