[A case of secondary malignant lymphoma of the urinary bladder]

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.