Mixed acinar-neuroendocrine carcinoma of the pancreas: A case report and a review

A 62-year-old woman presented with abdominal discomfort. Imaging studies showed a tumor in the pancreatic tail. At contrast-enhanced CT and macroscopy, the tumor showed cystic, solid and hemorrhagic areas. Histologically, the tumor was wellcircumscribed and entirely encapsulated. Some of the tumor cells in the cystic areas were reminiscent of acinar cells, and the majority was arranged in a solid growth pattern. Immunohistochemistry revealed >30% positivity for chymotrypsin, chromogranin A, synaptophysin, and CD56. The diagnosis of a mixed acinar-neuroendocrine carcinoma (MAEC) was made. Review of the English language literature revealed 44 previously published cases of resected MAECs. We found that, compared to pure acinar cell carcinoma, patients with MAEC have a slightly higher age and are less frequently males, as the male/female ratio was almost equal. The histogenesis of MAEC is still controversial. Due to the small number of cases it is at present not possible to define an evidencebased optimal treatment strategy for these patients.