中村 みちる¹, 谷口 信行¹, 川井 夫規子¹, 久力 権², 菅谷 泰宏³, 伊東 紘一¹

Michiru NAKAMURA¹, Nobuyuki TANIGUCH¹, Fukiko KAWAI¹, Ken KURIKI², Yasuhiro SUGAYA³, Kouichi ITOH¹

¹自治医科大学臨床病理, ²自治医科大学病院病理, ³自治医科大学病院泌尿器科

¹Department of Clinical Pathology, Jichi Medical School, ²Department of Pathology, Jichi Medical School, ³Department of Urology, Jichi Medical School

キーワード : Ultrasonography, Urachal remnant

Urachal remnats in children have been reported to be detectable by ultrasonography. We studied 220 asymptomatic bladders of people ranging from neonates to elderly in order to determine prevalence, size, and sonographic characteristics of urachal remnants. A homogenous hypoechoic mass was present in the upper anterior bladder walls, some showed continuity with the upper abdominal wall. These masses were detected in more than half of the population under 30 years of age; rate of detection decreased rapidly after age 30. The masses appeared less frequently in infants than in older children. Pathologic study of the mass in one case of cystitis showed it to be a urachal remnant that had undergone inflammatory change. Masses that appear to be urachal remnants on ultrasonographic examination are not rare in the anterior walls of the bladders of young individuals. It is important to keep this in mind in order to avoid mistaking the remnant for a pathologic tumor.