Multiple endocrine neoplasia type 1‐associated cystic pancreatic endocrine neoplasia and multifocal cholesterol granulomas

A novel combination of tumors was found in a 68 year‐old female with Multiple Endocrine Neoplasia type‐1 (MEN 1) that included a cystic pancreatic endocrine neoplasm (CPEN), a pituitary adenoma, and multifocal cholesterol granulomas (MCGs) in the breast, pleura, and the extremities. The pancreatic tumor displayed a single central locule surrounded by a thin rim of neoplastic parenchyma. The tumor showed heterogeneity in the architecture that included glandular, trabecular and solid patterns. The tumor cells of the pancreas were immunohistochemically positive for both endocrine and pancreatic acinar markers including chromogranin A, synaptophysin, glucagon, lipase, and reg protein. Electron microscopy revealed that there were numerous smaller dense‐cored neurosecretory granules, larger zymogen‐like granules and microvilli on the apical side of the tumor cells. The pancreatic tumor was diagnosed as CPEN with acinar cell features. Analysis of the DNA extracted from the tissues revealed that there is a MEN1 germline mutation in exon 10 codon 527, and somatic mutation in exon 2 codon 32 in the pancreatic tumor, and one base pair deletion in exon 2 codon 79 in the pituitary adenoma. Here, we report the case and discuss possible pathogenesis of CPEN and MCGs in a patient with MEN 1.