Abstract
Malignant neoplasms sometimes contain calcifications. However it is very rare that the ossification is seen in the tumor tissue. In this paper, we report a case of undifferentiated carcinoma of the transverse colon with ossification. The patient was a 63-year-old man who was diagnosed as having advanced transverse colon carcinoma with multiple liver metastases and peritoneal dissemination. Partial resection of the transverse colon and omentectomy were performed. The pathological examination revealed that the tumor was undifferentiated carcinoma with an area of squamous cell carcinoma-like, basal cell carcinoma-like or choriocarcinoma-like components. Interestingly, the ossification was seen in part of the tumor tissue. In the literature, there are not many reports on malignant tumors with ossification. As for the mechanism of ossification, involvement of the metaplastic change from fibroblasts to osteoblasts can be suspected in this case.
