扁平上皮分化を伴った移行上皮癌が経過中に広範な扁平上皮内癌の形をとった1例

Abstract

62歳女。肉眼的血尿を主訴とした。他院にて経尿道的膀胱腫瘍切除術(TUR-Bt)を受け、病理診断はtransitional cell carcinoma(TCC) G2 > squamous cell carcinoma(SCC)であった。3年後に再発を認めTUR-Btを受け、病理診断はTCC G2であった。膀胱全摘除術の可能性を指摘され、膀胱温存希望にて当科初診となった。経尿道的膀胱生検を行い、病理診断は11ヶ所中10ヶ所でTCC with squamous differentiation、G1-G2、pTisで、膀胱上皮内癌の診断でBCG膀胱内注入療法を7回施行した。約半年後、膀胱鏡で多発する乳頭状腫瘤を認めTUR-Btを行い、腫瘍5ヶ所に加え7ヶ所より生検を行い、病理診断はTCC with squamous differentiation、G1-G2、pTaであった。塩酸ピラルビシン膀胱内注入療法を10回行い、治療効果は良好であったが、その後の膀胱鏡検査で乳頭状腫瘤を認めた。TUR-Bt、膀胱生検を行い、病理組織は全ての組織でSCC、G1、pTisが疑われ、膀胱全摘除術、回腸導管造設術を行った。全摘標本では乳頭状病変はなく、ほぼ全ての粘膜が重層扁平上皮成分で置換されていた。扁平上皮化生を思わせる部分と秩序だった分化を喪失した異型を有する扁平上皮がみられた。異型細胞周囲には細胞間橋がみられた。免疫染色では異型上皮部で高頻度にp53、Ki-67陽性細胞を認めた。一部化生性変化との鑑別が困難であるが、異型細胞が重層扁平上皮由来であり、免疫染色の結果も考慮して扁平上皮内癌を疑ったが、これまでの経過より広範に扁平上皮内癌の形をとったTCCと診断した

In August 2000, a 62-year-old woman presented to another municipal hospital with macroscopic Transurethral resection of bladder tumor (TUR-Bt) was performed. The pathological hematuria. diagnosis was transitional cell carcinoma (TCC), G2 > squamous cell carcinoma (SCC). TUR-Bt repeated in July 2003 indicated recurrence. The pathological diagnosis was TCC, G2. She was referred to our hospital in August 2003 because she desired bladder preservation. After cystoscopy and random biopsy, pathological diagnosis was TCC with squamous differentiation, G1-G2, pTis. She received 7 weekly intravesical bacillus Calmette-Guerin (BCG) instillations. In April 2004, TUR-Bt was repeated and multiple recurrences were found. The pathological diagnosis was TCC with squamous differentiation, G1-G2, pTa. She received 10 weekly intravesical Pirarubicin hydrochroride instillations. In August cystoscopy and random biopsy were performed for evaluation of the intavesical instillation treatment. Pathological diagnosis was atypical squamous cells. In November, cystoscopy revealed recurrence of a bladder tumor. After admission, a small papillary tumor and multiple flat lesion biopsies demonstrated SCC without obvious invasion. The patient underwent cystectomy. There were widespread areas of full thickness squamous atypia. Most of the bladder did not show appearance of typical TCC, but the final pathological diagnosis was TCC because the case developed from TCC and could not be diagnosed as pure SCC. The diagnosis of SCC in situ of bladder is difficult, and this may contribute to its rarity.