腎盂に弁膜様構造物を認めた腎盂尿管移行部狭窄症の1例

Abstract

9歳女.3歳頃から時々発熱していたが, 今回に腎盂炎といわれて精査の為, 入院した.静脈内腎盂造影で左腎は腎杯の一部が薄く造影されるのみであったが, 逆行性腎盂造影で腎盂尿管移行部(PUJ)の狭窄と水腎症を認め, そのすぐ上位の腎盂にはくびれがみられた.腎盂形成術を施行したがPUJの高度な狭窄があり, その上部腎盂のくびれに相当して半月様弁膜様隆起があり, それを含めたen bloc切除, dismembered Y-plastyを行った.弁膜様隆起物は組織学的に上皮細胞を欠く粘膜と粘膜下組織, 平滑筋層よりなり, 外膜を欠いていた.尿管弁膜の報告は多いが, 腎盂内の弁膜や弁膜様隆起は未だ報告されていない

A 9-year-old girl visited our clinic with recurrent high fever as her chief complaint. Her excretory urogram showed only a few dilated upper calyces. Retrograde pyelography revealed ureteropelvic junction stenosis with hydronephrosis, so that the ureteral catheter could not be passed through the ureteropelvic junction. A fold-like filling defect was also seen above the ureteropelvic junction. At operation the ureteropelvic junction was found to be markedly obstructed, and a semilunar valve-like structure was also observed above it. The valve-like structure was seen where the fold-like filling defect appeared on the retrograde pyelogram. En bloc resection of the lower part of the renal pelvis with the valve-like structure and the ureteropelvic junction was performed, followed by dismembered uretero-pyeloplasty. Histologically, the valve-like structure was a transverse mucosal fold with a muscle layer and without adventitia.Many cases of ureteral valves have been reported, but none with valves or valve-like structures within the renal pelvis as in our case.