尿膜管に発生した扁平上皮癌

A case of squamous cell carcinoma in urachus

　84歳の男性に発生した尿膜管扁平上皮癌の1例を経験した。主訴は肉眼的血尿と下腹部痛。腹部CT，MRIにて膀胱頂部から前壁に囊胞様領域を伴う8×7×6cmの腫瘍を認め，膀胱部分切除による腫瘍摘除を施行した。発生部位・発育形態から尿膜管腫瘍と考えられ，病理学的には扁平上皮癌と診断された。癌細胞は敷石状配列し，その一部にはsingle cell keratinizationが認められた。この症例の臨床経過を報告するとともに，尿膜管扁平上皮癌につき文献的考察を行った。

An 84-year-old male was admitted to our institution complaining of macroscopic hematuria and lower abdominal pain. Computed tomography and MRI depicted an 8×7×6cm mass with cystic lesion in the supravesical portion. Under the diagnosis of an urachal tumor,he underwent tumor resection with partial cystectomy. Moderately to poorly differentiated squamous cell carcinoma was demonstrated on pathological examinations. Microscopically,carcinoma cells were arranged with cobble stone appearance,and part of them showed single cell keratinization. The clinical entity of this rare disease is reported and briefly discussed.（Rinsho Hinyokika 58：311-313,2004）