Carcinosarcoma of the stomach with endocrine differentiation. A case report

An unusual tumor was observed in a 67-year-old man. Microscopically, the tumor was composed of epithelial cells forming glands (CEA, EMA-positive) and spindle-shaped cells (vimentin-positive). A third component was a cell population ultrastructurally characterized by intracytoplasmic granules surrounded by a membrane; these proved to be chromogranin A-positive in the immunoperoxidase study.