Gastric adenocarcinoma is the second most common cause of cancer death worldwide, but there are some geographical differences in its incidence. Gastointestinal stromal tumor (GIST) is an uncommon disease with a wide spectrum of aggressive behavior. These two tumors have a distinct pathogenesis. GIST is frequently identified as an incidental lesion found by routine endoscopy or in resection specimens that are removed for other reasons. We report a case of a gastric adenocarcinoma mimicking GIST in a 79-year-old woman. GIST was suggested by endoscopic ultrasonography and computed tomography scanning, but gastric adenocarcinoma was confirmed by gastroduodenoscopic biopsy. We performed a subtotal gastrectomy with Billroth I, lymph node dissection and transverse colon segmentectomy, and a 15.0x7.5x5.5 cm-sized gastric tumor was confirmed pathologically. Immunohistochemistry was positive for carcinoembryonic antigen and focal weakly positive for cytokeratin7 and cytokeratin20.
Adenocarcinoma ; Aged ; Biopsy ; Carcinoembryonic Antigen ; Colon, Transverse ; Endoscopy ; Endosonography ; Female ; Gastrectomy ; Gastroenterostomy ; Gastrointestinal Stromal Tumors ; Humans ; Immunohistochemistry ; Incidence ; Lymph Node Excision ; Mastectomy, Segmental