Bladder mucosa-associated lymphoid tissue lymphoma progressed from chronic cystitis along with a comparative genetic analysis during long-term follow-up: a case report

The pathogenesis of bladder marginal zone/mucosa-associated lymphoid tissue (MALT) lymphoma, which is the most common type of primary bladder lymphoma, has not been clarified. There are no reports that described histological and molecular time course of MALT lymphoma occurring in the bladder and the importance of the score on the Pelvic Pain and Urgency/Frequency (PUF) patient symptom scale during and after radiation therapy (RT). We present a case of MALT lymphoma with long-term comparative genetic analysis. A 77-year-old Japanese woman with hematuria and severe perineal pain was found to have a tumor-like lesion in the bladder trigone. She was diagnosed with cystitis based on the results of pathological examination and immunostaining after transurethral resection of the lesion. The second transurethral resection procedure was performed approximately 4 years after the first procedure because of recurrence of the hematuria and enlargement of a lesion in the left bladder wall. Postoperative pathologic examination confirmed a diagnosis of MALT lymphoma. Genetic analysis of immunoglobulin heavy chain (IGH) gene rearrangements showed more clonal progression from the first biopsy to the second. The patient then underwent RT, during which her perineal pain was exacerbated by radiation cystitis but finally decreased to a level less severe than that before treatment. The PUF patient symptom scale was useful to monitor her pain throughout the clinical course. No recurrence was detected more than 2 years after completion of RT.