Pancreatic acinar cell carcinoma with pleomorphic and spindle cells: An autopsy-proven case.

Pancreatic acinar cell carcinomas are glandular and have amphophilic/eosinophilic cytoplasm, presenting acinar, solid, and trabecular structures. Unusual histological features of acinar cell carcinoma are known, such as oncocytic, pleomorphic, spindle, and clear cell variants, but their clinical significance has not been well described. A man in his 70s was referred to our hospital because of elevated serum pancreatic enzymes. Contrast-enhanced abdominal computed tomography revealed slight swelling of the pancreatic head and suspension of the main pancreatic duct in the pancreatic body. He died only 14 days after admission. Gross findings at autopsy showed an ill-defined tumor located in the pancreatic head, involving the gastric and duodenal walls. Peritoneal dissemination, liver metastases, and lymph node metastases were also observed. Microscopically, tumor cells had moderate-to-severe nuclear atypia and amphophilic cytoplasm showing pleomorphism, and diffusely proliferated in solid pattern without lumina, were admixed with spindle cells. Immunohistochemically, tumor cells including pleomorphic and spindle cells were positive for B-cell lymphoma/leukemia 10 and trypsin. Consequently, the diagnosis was pancreatic acinar cell carcinoma with pleomorphic and spindle cells. We encountered a rare variant of pancreatic acinar cell carcinoma with pleomorphic and spindle cells. Clinically, our case showed rapid progression.