A rare case of plexiform angiomyxoid myofibroblastic tumor in the stomach which was diagnosed at the earliest stage in the literature

Abstract

Plexiform angiomyxoid myofibroblastic tumor (PAMT) is a rare gastric mesenchymal entity with a peculiar plexiform pattern, bland spindle cells and myxoid stroma rich in arborizing blood vessels. Here we report a 44-year-old Chinese woman with PAMT. Initially she was admitted for removal of a gastric antral'polyp' found on a routine examination 5 months previously. Our gastroscopy showed a 0.8 × 0.8 cm polyp-like mass in the antrum which protruded into the lumen. Endoscopic submucosal dissection (ESD) was performed to remove this mass en bloc. The specimen was carefully examined by pathologists, and the correct diagnosis of PAMT was finally made. The tumor in this case depicted typical histopathological and immunohistochemical features of gastric PAMT. This PAMT was not only the smallest on endoscopic examination in the literature but also-unlike the already reported PAMTs-exhibited a focal hyperechogenic lesion on endoscopic ultrasonography (EUS). This information highlights its value on how to identify a PAMT at its early stage.

Keywords: diagnosis; endoscopic ultrasonography; gastrointestinal stromal tumors; plexiform angiomyxoid myofibroblastic tumor.