多発性痔瘻症例の摘出瘻管の組織所見 Histopathological Features of Excised Fistulous Tracts in Cases with Multiple Anal Fistulas

目的, 対象と方法 : 一次口を別にする瘻管を2本以上をもつ痔瘻33例 (男性31人, 女性2人) 瘻管総数67本について瘻管を完全切除し, その組織像を検索した. 結果 : 多発性痔瘻では外括約筋を貫く肛門管に対し放射状に直走する瘻管, 組織型では瘻管形成型 (37/67) が多く, 一次口の位置では6時位 (18/67) に多かった. 瘻管内に肛門腺を認める症例は49% (33/67) であり, IV型痔瘻はなかった. 瘻管組織の特徴は, 膿瘍併存型痔瘻でも脂肪組織内に炎症細胞の浸潤を認めるものの, 膿瘍を強く形成する症例はなかった. 瘻管形成型, 膿瘍併存型痔瘻にみられる肛門腺は分葉型 (20/33) を多く認めた. 円柱上皮と移行上皮で構成される管壁では腺管破壊像と粘液産生能を認めたが, 扁平上皮化生で構成される肛門腺は, 管壁の破壊像, 粘液産生能はなく, 管壁周囲の炎症は軽度あるいは消退していた. 結論 : 多発性痔瘻の瘻管は, 炎症性細胞の浸潤は弱く, 肛門腺の関与する割合は半数以下であり, 肛門腺は感染に弱いが扁平上皮に化生するため炎症は消退しやすいと推測された.

Histological features were investigated in 33 cases (31 males and two females) who had more than two fistulas originating in different internal openings. Sixty-seven percent of anal fistulas (45/67) were taken through the external anal sphincter and 27% of internal openings (18/67) were found at the 6 oclock position. An anal gland was observed in fistulous tracts in 49% of cases (37/67). The fistulous tract for most types extended in a radial direction to an external opening. There were no cases with supralevator fistula. A few cases, even in the type of fistulous tract with abscess, were found to have abscess formation in the adipose tissues, even though inflammatory cells had permeated into the surrounding adipose tissue. Many branched types of anal glands were recognized in the tracts of the fistulas with or without abscess. The anal gland wall, which was lined with stratified columnar or transitional epithelia in which mucous secretion was observed, was destroyed. However, outbreak of the glandular wall was not noticed in the metaplastic squamous epithelia, which did not produce mucus. It is concluded that anal fistulas with multiple internal openings did not tend to spread inflammation, transformed into an anal gland lined with squamous metaplastic epithelia and tended to cease inflammation along the fistulous tracts, whereas the gland lined with columnar epithelia was easily infected.