History:

A 22-year-old female patient has presented with a history of multiple nodular lesions within the stomach. She also has a past history of multiple, similar tumors in the stomach, which required resections, along with a history of Imatinib therapy. Her post treatment response has been poor. The following images are from the gastrectomy specimen. The sections show a multinodular/plexiform tumor in the gastric submucosa, composed of sheets of epithelioid cells with mid atypia, eosinophilic cytoplasm, and 0-1 mitosis per 5 mm². The tumor cells are positive for DOG-1 and CD-117 immunostains. Taking her history into account, an additional immunostain was performed on the gastrectomy specimen (also shown below).