陰嚢に開口する副尿道の1例

Abstract

60歳男。幼少期より陰嚢部の瘻孔を自覚し, また時に排膿を認めたが自然軽快するため放置していた。膿性分泌物の増加を認め, 近医で瘻孔除去術を受けたが残存する瘻孔が球部尿道付近に及び, 陰嚢皮下に索状硬結を触れるため, 手術目的で当院紹介入院となった。陰嚢縫線上に瘻孔開口部を認め, 5cm長の索状硬結を触れ, 著明な圧迫を認めた。MRI矢状断で瘻孔は陰嚢皮膚より起始して球部尿道に近接し, 排膿培養ではE.coliが検出された。副尿道摘除術, 瘻孔摘除術を施行した。球海綿体筋, 坐骨海綿体筋の筋膜に沿って存在する瘻孔は骨盤底筋付近に達しており, 瘻孔の断端部位で結紮・切断した。全長約13cmで尿道との交通はなく, 摘出物は近位に移行上皮, 遠位に重層扁平上皮を認めたが, 海綿体組織は認めなかった。陰嚢縫線周囲の硬結, 疼痛は消失した。

A 67-year-old male had an innate fistular orifice at the scrotal skin. In spite of occasional pus discharge from the orifice, no treatment had been performed for the fistula because it improved spontaneously. Due to increasing pus discharge, the fistula was resected at a dermatology clinic, but a persistent fistula tract was confirmed postoperatively by MRI. The fistula adjoined the bulbar urethra and was considered an accessory urethra. We performed resection of the fistula to resolve the frequent pus discharge and pain due to infection of the fistula. The isolated fistula did not communicate with the urethra and the proximal edge ended blindly. Pathological examination showed that the proximal end consisted of transitional epithelium and the distal end consisted of stratified squamous epithelium which meant an accessory urethra. Accessory urethra is not a rare condition, but cases like this one with an orifice that opened at the scrotal skin are extremely rare. As the treatment for the fistula, complete resection should be indicated.