著明な粘液産生がみられた主膵管内乳頭腺腫の1例

Intraductal Papillary Adenoma of the Pancreas Showing Rich Production of Mucin, Report of a Case

要旨　患者は74歳，男性．無症状であるが糖尿病の経過観察中，血清アミラーゼ上昇がみられ，USで膵病変が発見された．US・CTでは主膵管が軽度拡張し，特に体部に27×10mmの囊状拡張がみられた．十二指腸内視鏡では主乳頭開口部の開大がみられ，ERP検査で主膵管は体部において囊状に拡張し内腔に陰影欠損像と可動性のある透亮像がみられた．以上から体部主膵管に発生した粘液産生膵癌を強く疑い，膵体尾部切除術を施行した．切除後の膵管鏡で主膵管内腔に多発したイクラ状の小隆起を確認した．病変は拡張した膵管内腔にあり，22×8mmの乳頭状隆起で，組織は乳頭状腺腫で異型は軽度であった．

　A case of a 74-year-old man is reported with intraductal papillary adenoma in the body of the pancreas showing type Ⅲ according to our ERCP classification.

　Although he had no complaints, there was a slight elevation of serum amylase level during the follow-up of diabetes mellitus which he had been suffering from. CT demonstrated localized dilatation of the main pancreatic duct in the body of the pancreas (Fig. 2). CT level of this lesion was not homogeneous. Endoscopically the orifice of the duodenal major papilla was observed to be open widely. ERCP demonstrated localized dilatation of the main pancreatic duct in the body of the pancreas (Fig. 3a). Several filling defects and translucencies were seen in the dilated duct. Mucinproducing cancer in the body of the pancreas was highly suspected due to the above abnormal findings, so distal pancreatectomy was carried out. Pancreatoscopy in the resected specimen demonstrated white and flat elevations with central redness on the epithelium of the main pancreatic duct (Fig. 6). Cross-sections of the resected specimen revealed papillary projections in the main pancreatic duct with a maximum length of 22 mm (Figs. 7b, c). Histological diagnosis was intraductal papillary adenoma in the body of the pancreas with slight atypia (Figs. 8 a, b).