ポリープ型を呈した男子傍尿道口嚢腫の1例

Abstract

45歳男.32歳時より精神分裂病を発症し, 入退院を繰り返しており, 15歳頃より外尿道口の腫瘤に気づいていたが放置していた.約10年前より腫瘤が徐々に増大し, 8ヵ月ほど前から尿線の散乱が著明となったため来診した.初診時, 外尿道口の口唇部より下垂する約1×1cm大球形の透光性のある腫瘤を認め, 腫瘤茎部は外尿道口左側縁に位置していた.同日, 局所麻酔下に外尿道口の腫瘤茎部の皮膚を円弧状に切開して腫瘤を摘出した.腫瘤内は無色透明な粘液で満たされており, 腫瘤内面を覆う上皮は平滑で, 毛髪や腫瘤は認められなかった.病理組織学的所見から本症例は粘液嚢腫と診断されたが, ポリープ状形を呈した傍尿道口嚢腫は自験例が日本で9例目にあたり, 年齢が45歳と高いこと, 嚢腫の大きさが1cmを越えるなど稀な症例と考えられた

A 45-year-old man first noticed a soft tumor on his left lip of the urethral meatus at the age of 15. The lesion had gradually been increasing in size during the last 10 years. He presented to our clinic with division of urinary stream which had been persisting for about nine months. The tumor was resected, and histopathological examination revealed that it was a mucous cyst. The cyst had an outer wall of stratified squamous epithelium and an inner wall of stratified columnar epithelium. Since the inner wall was covered with epithelium originating from the urethral mucosa and the lesion was located outside the urethral meatus, a diagnosis of parameatal urethral cyst was made. Recently, parameatal urethral cyst has rarely been reported since it is often clinically in significant and remains asymptomatic. In our patient, the tumor showed polyploid growth and caused difficulty in urination. The mechanism of its development is considered based on a review of the literature.