術前に診断しえた虫垂粘液囊腫の1例

Mutinous Cystadenoma of the Appendix Diagnosed before Operation, Report of a Case

要旨　各種画像検査にて特徴的な所見を示し，術前に診断しえた虫垂粘液囊腫の1例を報告した．患者は52歳，男性．右下腹部腫瘤を主訴として来院．注腸X線検査では虫垂は造影されず，盲腸下極に粘膜下腫瘍を思わせる表面平滑な半球状の陰影欠損を認め，上行結腸外側になだらかな管外性圧排像が見られた．大腸内視鏡検査では，隆起および上行結腸の圧排所見は，体位，空気量により形状の変化が認められた．腹部超音波・CT検査にて，盲腸に接し頭側に棍棒状に連続する囊胞性病変が見られた．以上より虫垂粘液囊腫と診断し，回盲部手術を施行した．切除標本肉眼所見では，淡黄色・透明なゼラチン様物質を含んで緊満し腫大した虫垂が認められ，病理組織学的に虫垂粘液囊胞腺腫と診断した．

　A 52-year-old man was referred to our clinic on October 17, 1990 with the chief complaint of right lower abdominal mass. A barium enema study showed a hemispherical, sharply circumscribed soft tissue mass projecting into the inferolateral region of the cecum, and an extrinsic suppression at the ascending colon. This mass changed shape according to position and air volume. We were unable to get a picture of the appendix. Colonoscopic examination showed a submucosal tumor at the bottom of the cecum, and an extrinsic suppression at the ascending colon. These phenomena also changed shape according to position and air volume. Ultrasonography demonstrated a cystic mass in which hyperechoic spots were present. An abdominal CT scan showed a low density cystic mass in the cecum. Angiography showed no malignant findings such as neovascularity encasement. As a result of these examinations, we diagnosed this as a case of mucinous cystadenoma.

　Ileo-cecal resection was performed. During the operation it was noticed that the appendix was swollen. Macroscopic finding of the resected specimen showed a markedly swollen appendix with abundant mucin, measuring 11.7×4.5 cm. Histological study showed columnar mucin-secreting epithelium of the cystic wall. Histological diagnosis was mutinous cystadenoma.