十二指腸乳頭部癌に合併した胆道回虫迷入症の1例

Biliary Ascariasis Associated with Cancer of the Duodenal Papilla, Report of a Case

要旨　54歳，女性．主訴は心窩部痛．腹部超音波検査で総胆管内に中空の索状影を認め胆道回虫迷入症を疑われ，ERCPで確診．虫体はEST，駆虫剤で自然排泄した．3か月後，再び心窩部痛出現ERCPで胆膵管の拡張と総胆管末端の陰影欠損像を認め，腫大した十二指腸乳頭部の生検で高分化型腺癌と診断され，膵頭十二指腸切除術を施行した．文献を見ると1980年以降，本邦胆道回虫迷入症の報告は19例で，回虫症は激減したが胆囊炎様症状を呈する急性腹症の際に本症は忘れてはならない．超音波検査で中空の索状影が認められればその診断は容易である．治療は，駆虫剤の使用や内視鏡的摘出など保存的に経過をみて，それに抵抗するものや，合併症のあるものが手術適応となろう．

　A 54-year-old female was admitted to our hospital because of repeated severe epigastric pain. She was diagnosed as having biliary ascariasis. The characteristic feature of this disease viz. “inner tube sign” (Schulman, et al) and dilatation of the bile duct were revealed by ultrasonography (Fig. 1). The diagnosis was also confirmed by ERCP (Fig. 3). The papilla of Vater (Fig. 2) was swollen and bled easily, and we interpreted these findings as inflammatory changes brought about by biliary ascariasis. EST was performed and vermifuges were administered orally. After that, a female ascaria was discharged (Fig. 5).

　She was admitted again because of the same symptom after two months. Sonography and ERCP (Fig. 7) showed dilatations of biliary and pancreatic ducts. Radiologically, filling defect was recognized in the distal common bile duct, and erosive or ulcerative change was found at the papilla of Vater endoscopically (Fig. 6). The histological finding was well differentiated adenocarcinoma. Pancreaticoduodenectomy was performed.

　Currently, ascariasis has become rare in Japan, but we should not forget biliary ascariasis in patients with acute abdominal pain who are suspected of having cholecystitis or cholelithiasis. Sonography was very useful for diagnosis and for indicating what surgical decision should be made. As conservative therapy including vermifuges and endoscopic extraction is occasionally effective, we should be aware that surgery may possibly be avoided.