HEMANGIOPERICYTOMA OF THE SIGMOID MESENTERY - REPORT OF A CASE WITH IMMUNOHISTOCHEMICAL FINDINGS

Hemangiopericytoma has been described in various sites in the body but only rarely in the mesocolon. This report describes the clinical cour se of an 83-year-old man whose mesosigmoidal tumor (hemangiopericytoma ) was resected on 11 November 1994. Immunostaining was done with the f ollowing primary antibodies: alpha-actin, vimentin, factor VIII-relate d antigen, chromogranin, and S-100. Staining for factor VIII-related a ntigen was strongly positive in the endothelial cells of the capillari es, but negative in the tumor cells. The tumor cells contained immunor eactive vimentin, but demonstrated no alpha-actin, chromogranin, or S- 100, Since the operation, the patient has been disease-free for 11 mon ths.