Plexiform Angiomyxoid Myofibroblastic Tumor of the Stomach: a Rare Case.

Plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach is a very rare mesenchymal tumor of the gastrointestinal tract. We report a case of asymptomatic gastric PAMT that was pathologically confirmed after surgical resection. The tumor had a multinodular plexiform growth pattern, bland-looking spindle cells, and an Alcian blue-positive myxoid stromal matrix rich in small blood vessels. Immunohistochemistry analysis revealed that the tumor cells of the PAMT were positive for smooth muscle actin (SMA) and negative for c-kit, CD34, S-100 protein, epithelial membrane antigen (EMA), and desmin. PAMT should be differentiated from other submucosal tumors of the stomach by immunohistochemical findings. Considering the benign features of this tumor, observation without resection may be an option for the treatment of PAMT if the tumor is asymptomatic.