A patient with a mixed acinar-neuroendocrine carcinoma with cystic degeneration

Abstract

We report a patient with a mixed acinar-neuroendocrine carcinoma and review of the literature. A 57-year-old man was referred for a cystic lesion in the pancreatic body for further evaluation. Contrast-enhanced computed tomography (CT) scan showed a 17mm mass with a cystic component. On CT scan 3 years later, the tumor with its cystic component had enlarged to 23mm. Magnetic resonance imaging showed a tumor with the central cystic component having a high signal intensity in T1- and T2-weighted images and the margin of the tumor had reduced diffusion. Endoscopic ultrasound depicted a solid mass with a central cystic component. This tumor was suspected to be a solid pancreatic tumor with cystic changes as seen with neuroendocrine tumors or acinar cell tumors. The tumor was resected and pathologically diagnosed as a mixed acinar-neuroendocrine carcinoma. The cystic component in the center of the tumor may have resulted from necrosis and hemorrhage. The components of the neuroendocrine neoplasm and acinar cell carcinoma were located near the cystic component and the periphery, respectively. This case strongly suggests a mechanism for mixed acinar-neuroendocrine carcinoma development.