2020 年 59 巻 5 号 p. 251-252
We report the case of a 59-year-old woman with pancreatic mixed adenoneuroendocrine carcinoma (MANEC) and liver metastasis. The EUS-FNA smear was hypercellular with neoplastic cells scattered in loosely cohesive clusters. The tumor cells had large round nuclei, coarse granular chromatin and light green cytoplasm. Although the diagnosis was suspected as NET or adenocarcinoma, the lack of a definite pattern and unclear differentiation prevented a definitive cytological differential diagnosis. Histopathological examination of the liver biopsy specimen revealed that the tumor nests contained intraluminal mucin and immunohistochemistry revealed that the cells were positive for neuroendocrine markers. Thus, we finally made the histopathological diagnosis of MANEC.