Osteosarcoma as Malignant Mural Nodule in Ovarian Mucinous Neoplasms of Intestinal Type: Report of 2 Cases

Mural nodules, which may be benign or malignant, are well recognized in ovarian mucinous neoplasms, especially of borderline type. Malignant mural nodules most commonly comprise anaplastic carcinoma but sarcomas of various types have been reported. We report 2 cases of osteosarcoma occurring in young women (aged 18 and 34) as malignant mural nodules in a Grade 1 ovarian mucinous carcinoma of intestinal type and a borderline mucinous tumor of intestinal type. Primary osteosarcomas of the ovary have been described either arising within a teratoma or as a pure neoplasm but, to the best of our knowledge, osteosarcoma occurring as a mural nodule in an ovarian mucinous neoplasm has not been reported. In both our cases, the tumor was Stage 1 at presentation and the patients were treated with surgery without adjuvant chemotherapy. Both patients are free of disease with follow-up of 12 and 18 mo.