Shibata Hideki, Ohike Nobuyuki, Norose Tomoko, Isobe Tomohide, Suzuki Reika, Imai Hideyuki, Shiokawa Akira, Takimoto Masafumi, Tabuchi Akihiro, Takano Yuichi, Yamamura Eiichi, Nagahama Masatsugu, Takeyama Nobuyuki, Yokomizo Kazuaki, Mizukami Hiroki, Tanaka Jun-Ichi, Aoki Takeshi, Murakami Masahiko
Department of Pathology, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, Yokohama, 227-8501, Kanagawa, Japan.
Department of Pathology, Showa University Hospital, Shinagawa, Tokyo, Japan.
Clin J Gastroenterol. 2017 Jun;10(3):274-278. doi: 10.1007/s12328-017-0728-1. Epub 2017 Mar 3.
The patient was a 60-year-old man without any particular complaints, but he underwent abdominal computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) due to a fatty liver, which revealed two similar cystic lesions regarded as branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) in the pancreatic body [BD-IPMN (b), 16 mm in size] and tail [BD-IPMN (t), 13 mm in size] without a "high-risk stigmata" or "worrisome features". He subsequently received follow-up by MRCP every 6 months. Two years later, MRCP showed prominent dilation of the main pancreatic duct (MPD) and mural nodule formation within the dilated MPD adjacent to the BD-IPMN (b). Distal pancreatectomy specimens revealed that the BD-IPMN (b) was lined by low-papillary gastric mucinous epithelium with low-to-intermediate-grade dysplasia and involved the MPD, forming a malignant mural nodule showing pancreatobiliary-type IPMN. In contrast, the BD-IPMN (t) was lined by flat, monolayer columnar gastric mucinous epithelium without atypia, which suggested the possibility of a "simple mucinous cyst". A genetic analysis showed KRAS mutation only in BD-IPMN (b). Differences in the histological and genetic findings between two similar BD-IPMNs in the present case may suggest what kinds of examinations should be performed in patients with BD-IPMNs without any worrisome features.
患者为一名60岁男性，无任何特殊不适，但因脂肪肝接受了腹部计算机断层扫描（CT）和磁共振胰胆管造影（MRCP）检查，结果显示在胰体部发现两个类似的囊性病变，考虑为分支导管型导管内乳头状黏液性肿瘤（BD-IPMN）[BD-IPMN（b），大小为16毫米]，胰尾部也有一个[BD-IPMN（t），大小为13毫米]，均无“高危征象”或“可疑特征”。随后他每6个月接受一次MRCP随访。两年后，MRCP显示主胰管（MPD）明显扩张，在与BD-IPMN（b）相邻的扩张MPD内形成壁结节。远端胰腺切除标本显示，BD-IPMN（b）内衬低乳头状胃黏液上皮，伴有低至中度发育异常，并累及MPD，形成一个显示胰胆管型IPMN的恶性壁结节。相比之下，BD-IPMN（t）内衬扁平的单层柱状胃黏液上皮，无异型性，提示可能为“单纯黏液囊肿”。基因分析显示仅BD-IPMN（b）存在KRAS突变。本病例中两个相似的BD-IPMN在组织学和基因学结果上的差异可能提示对于无任何可疑特征的BD-IPMN患者应进行何种检查。
