Acinar cell carcinoma arising in the stomach: a case report with literature review.

Acinar cell carcinomas (ACCs) are uncommon malignant tumors of the exocrine pancreas, constituting 1% to 2% of all nonendocrine pancreatic neoplasms. Cases of acinar cell carcinoma developing in heterotopic pancreatic tissue are extremely rare. To the best of our knowledge, no cases of primary ACC developing in the stomach have been reported in the literature. We report the first case of a primary ACC arising in the stomach in an 86-year-old female who presented with a 5-cm gastric submucosal mass with superficial ulceration and a history of anemia. The neoplasm exhibited typical acinar morphology. Immunohistochemical studies demonstrated strong positive reactivity for antitrypsin and antichymotrypsin, and electron microscopy confirmed the presence of zymogen granules. A complete metastatic workup failed to identify any primary pancreatic tumor or other nonpancreatic tumor.