粘液を有する膵小囊胞の3例

Small Mucin-producing Cystic Tumor of the Pancreas, Report of Three Cases

要旨　特異な膵管像を呈した粘液を有する膵小囊胞の3例を経験した．いずれも上腹部痛を主訴とし，現症・生化学検査上は異常なく，発見の契機はERP（2例），US（1例）であった．US，CTでは存在診断を行いえたが，ERPが病変の存在，性状を診断するのに有用であった．膵管像は小囊胞内の陰影欠損とこれに連なる主膵管内の粘液を思わせる透亮像が特徴的であり，十二指腸乳頭は正常像を示した．組織学的にはmUcinous cystadenoma（2例），retention cyst（1例）と診断された．粘液産生腫瘍の初期とも老えられ，興味ある症例であった．

　Three patients with small cystic tumor of the pancreas were described (Table 1). They had upper abdominal pain as their symptom. Physical findings and laboratory values were normal except for glucose tolerance test. Endoscopic retrograde pancreatography (ERP) played a crucial role for diagnosis, showing a small cystic formation communicating with the main pancreatic duct. Linear filling defects seen in the main pancreatic duct seemed to be due to mucin produced by the tumor (Figs.1, 2, 6, 8). These findings are similar to those of mucin-producing pancreatic cancer, which has recently drawn attention because of the characteristic, macroscopic and pathological findings as well as the favourable prognosis. By histology, however, the lesions in these patients were mucinous cystadenoma (case 1, 2) and retention cyst (case 3) lined by epithelium with cytoplasm containing abundant mucin. The similarity of the ERP and microscopic fiindings between these lesions and mucinproducing carcinoma, are of interest, because of the possible etiologic relationship which may exist between them.