GROSS DESCRIPTION: The specimen consists of a partial gastrectomy measuring 15 x 101 x 7 cm. Attached to the wall of the stomach is a large cystically dilated mass measuring 21 x 16 x 12 cm. Opening of the mass shows a tumor arising from the wall with a cystic component filled by blood.
SPECIAL STUDIES: The tumor cells are positive for C-kit and CD34, negative for CK, desmin and S-100.
DIAGNOSIS: Epitheloid gastrointestinal stromal tumor.