Plexiform angiomyxoid myofibroblastic tumor of the stomach: A case report.

Plexiform angiomyxoid myofibroblastic tumor (PAMT) is a rare mesenchymal tumor of the stomach. To date, about 40 cases of PAMT have been reported in the literature. This tumor is not specific in clinical manifestations and microscopically characterized by a plexiform growth pattern. Here, we report the case of an 11-year-old male patient who was diagnosed with PAMT. He had a complaint of right epigastric discomfort with episodic pain, gastroscopy displayed a submucosal bulge at the pylorus, and CT showed a mass in the right abdomen with uneven, delayed enhancement, and a partial gastrectomy revealed a tumor at the pylorus. Histologically, the tumor was multinodular and rich in blood vessels with thin wall; the interstitium had abundant myxomatous stroma; the tumor cells were spindle-shaped, star-shaped, or oval. Immunohistochemically, the tumor cells were positive for Calponin, Caldesmon, and SMA, but negative for CD34, ALK, S-100, desmin, CD117, and Dog-1. This patient was followed up for 12 months, and recurrence or metastasis was not observed. Diagn. Cytopathol. 2017;45:55-58. © 2016 Wiley Periodicals, Inc.