A case of chronic pancreatitis occurring in gastric aberrant pancreas poorly distinguishable from gastric aberrant pancreas ductal carcinoma

A man in his 40s was referred to our hospital with abdominal pain. A gastric submucosal tumor (SMT) was diagnosed nine years previously, but the patient was lost to follow-up. Upon our evaluation, the SMT had enlarged, as demonstrated by esophagogastroduodenoscopy and abdominal computed tomography. Endoscopic ultrasonography revealed a hypoechoic and isoechoic mosaic mass, which primarily occupied the third and fourth layers of the gastric wall. Aspiration cytodiagnosis was performed, the results of which led to a suspicion of adenocarcinoma arising from gastric ectopic pancreas. Next, we conducted segmental gastrectomy. Pathological examination showed adiponecrosis, a pancreatic stone, chronic inflammatory cell infiltration, and fibrosis. Thus, the patient was diagnosed with chronic pancreatitis occurring in a gastric aberrant pancreas.