膀胱に続発した悪性リンパ腫の1例

Abstract

56歳男.悪性リンパ腫, Diffuse large B cell type, clinical stage IIIbと診断され, シクロスファミド・塩酸ドキソルビシン・塩酸ビンクリスチン・プレドニゾロンによるCHOP療法で完全緩解を得た.しかし, その後再発し, イフォスファミド, エトポシド, ミトキサントロンによるMINE療法1コース終了後, 膀胱内に多発する腫瘤を指摘された.MINE療法2コース終了後, 膀胱鏡検査で, 右尿管口奥に約1cmの単発の非乳頭状広基性腫瘍がみられた.MINE療法3コース終了後, 膀胱悪性リンパ腫, 或いは原発性膀胱癌の疑いで経尿道的膀胱腫瘍切除術を行った.膀胱鏡で認められた隆起性病変は消失し, 瘢痕化していた.同部の生検所見は, 小型のリンパ球と共に大型の異型細胞が正常な尿路上皮下への浸潤がみられ, L-26(CD20)は異型細胞のほぼ全てに強陽性であった.膀胱内に続発した悪性リンパ腫腫と診断し, MINE療法の効果を期待して, 継続中である

A 56-year-old man was admitted to our hospital for salvage chemotherapy of recurrent diffuse large B cell malignant lymphoma at clinical stage IIIb and which had been treated with 6 cycles of cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP). Computed tomography showed multiple tumors in the bladder after a cycle of ifosfamide, etoposide and mitoxantrone (MINE), but cystoscopy after the second cycle revealed a single non-papillary tumor about 1cm in diameter. After 3 cycles of MINE therapy, transurethral resection of bladder tumor was performed. At the time of the operation, the protruded lesion disappeared and there remained only a scar. Biopsy of the scar revealed malignant lymphoma infiltrated into the submucosal layer. Although the rate of the bladder involvement of malignant lymphoma reaches 3-20% in autopsy cases, it is very rare for a secondary malignant lymphoma of the urinary bladder to be diagnosed clinically. The prognosis of the secondary bladder lymphoma is much poorer than that of the primary one, because of the widespread dissemination of the disease at the time of diagnosis.