RESUMEN
Primary low-grade lymphoma of the mucosa-associated lymphoid tissue (MALT) type lymphoma of the bladder is rare. A relationship between MALT lymphoma of the urinary bladder and chronic cystitis has been proposed by some reports. Additionally a relationship between MALT lymphoma of the urinary bladder and Helicobacter pylori has been reported. Here we present a case of regression of urinary bladder MALT lymphoma after antibiotic therapy, using H. pylori eradication protocol in an elderly patient, who had a high risk of treatment related mortality in curative systemic chemotherapy. The patient is a 74-year-old woman who had a history of chronic cystitis. She was diagnosed with stage IIA primary MALT lymphoma of the urinary bladder and was treated with H. pylori eradication triple therapy for 2 weeks. After 2 months, there was a marked regression of the bladder MALT lymphoma lesion in a computed tomography scan of the abdomen.