Ovarian mucinous cystic tumor with sarcoma-like mural nodules and multifocal anaplastic carcinoma: a case report.

A 48-year-old woman presented with left abdominal pain and fullness. Computed tomography scan revealed a multicystic mass with multifocal mural nodules. Histologic examination showed a mucinous cystic tumor with cystadenoma, borderline malignant cystadenoma and cystadenocarcinoma, which were associated with sarcoma-like mural nodules (SLMNs) and multifocal anaplastic carcinoma. Mural nodules showed a positive reaction for CD56 and vimentin, but were negative for cytokeratin 7 and SMA. She underwent postoperative chemotherapy and is currently under follow-up; no recurrence or metastases were found in the first year of follow-up. Ovarian mucinous cystic tumor with SLMNs and foci of anaplastic carcinoma is extremely rare. To our knowledge, this case reports the most complex neoplastic and reactive components. Our findings shed some light on the pathogenesis of this rather rare carcinoma. We think that the formation of SLMNs may be the result of the reactive proliferation of undifferentiated mesenchymal cells, while the anaplastic carcinoma may be derived from mucinous epithelium. Moreover, because of difficulties encountered in their differential diagnosis, we think that the existence of foci of anaplastic carcinoma along with SLMNs necessitates careful histologic and immunohistochemical analysis of mural nodules for the determination of treatment and prognosis.