Abstract
Background : We report a case of mixed adenoneuroendocrine carcinoma (MANEC) arising from the biliary tract with the finding of intermediate cells.
Cases : A-60s man old man presenting with jaundice was detected to have a nodule in the common bile duct, and brush sampling of the biliary tract was performed. Based on the preoperative cytological findings suggestive of adenocarcinoma, cholecystectomy with partial resection of the biliary tract was performed.
Cytology of the biliary tract revealed intermediate cells of between adenocarcinoma and neuroendocrime carcinoma (NEC), with large nuclei and a high N/C ratio. Exfoliative bile juice cytology revealed the diagnosis of adenocarcinoma. Large oval cells with high N/C ratios and a fine nuclear chromatin pattern were observed on intraabdominal lavage cytology performed during the surgery, indicative of NEC,
Histologically, small round-CD56 positive cell clusters with high N/C ratios were identified in the submucosa, associated with adenocarcinoma of the mucosal surface. Based on the findings, a final histopathological diagnosis of MANEC was made.
Conclusion : The cytological findings can differ depending on the cytological material examined and the method used to obtain it, depending on the depth histologic variation of MANEC from which the material is obtained. When intermediate cells showing overlapping features between adenocarcinoma and NEC are found, the possibility of MANEC should be borne in mind.
