Primary gastric adenosarcoma.

We describe the first case, to our knowledge, of a primary gastric adenosarcoma surgically resected from a 46-year-old white man. This biphasic neoplasm, well described in the female genital tract, was composed of cytologically benign tubular and cystic glands widely dispersed within a sarcomatous stromal component. Immunohistochemically, the epithelial elements were positive for cytokeratin, while the stromal elements were positive for vimentin and desmin. The clinical and pathologic features of pelvic adenosarcomas are described and compared with the tumor of the stomach. Although accurate prediction of the biologic behavior of this gastric neoplasm is difficult, the high mitotic rate in the sarcomatous component and the infiltration of the gastric serosal surface by the tumor were considered to be ominous prognostic features.