Bone metaplasia in ovarian metastasis of colorectal carcinoma.

A 76-year-old female patient with mucinous adenocacinoma of the hepatic flexure. During hemicolectomy an ovarian tumor was observed and removed. Histological study of the adnexal lesion reveals metastasis of colorectal carcinoma with presence of bone metaplasia in the adjacent stroma. This rare finding consists of the formation of benign bone tissue induced by substances secreted by the tumor cells, and can be found in both malignant and benign lesions.