Ovarian mucinous tumors with foci of anaplastic carcinoma.

Four ovarian mucinous cystic tumors that contained solid nodules of anaplastic carcinoma in their walls are described. All the tumors had metastasized at the time of or shortly after operation and two have already proven fatal. The anaplastic nodules may be confused on gross and microscopic examination with sarcomas and sarcoma-like nodules, both of which may also be encountered in the wall of mucinous cystic tumors. Although the distinction of foci of anaplastic carcinoma from foci of sarcoma may not have prognostic significance, both of them should be separated from sarcoma-like nodules because of the favorable prognosis associated with the latter. In favor of a diagnosis of anaplastic carcinoma are poor circumscription of the nodules, vascular invasion and absence of a prominent inflammatory reaction with multinucleated giant cells of the epulis type.