Successful radiation therapy for primary mucosa-associated lymphoid tissue lymphoma of the prostate

Abstract

We report a case of primary mucosa-associated lymphoid tissue (MALT) lymphoma of the prostate. A 57-year-old man complained of dysuria, nocturia, and sensation of residual urine for 3 years. The laboratory data showed that the serum prostate-specific antigen (PSA) level was 5.2 ng/mL. A physical examination revealed mild prostate enlargement and no lymphadenopathy. Magnetic resonance imaging (MRI) suggested benign prostatic hyperplasia. A transrectal ultrasound-guided prostate needle biopsy was performed and the prostatic tissues of the biopsy showed the features of MALT lymphoma. And then complete clinical investigation, including bone marrow biopsy and positron emission tomography (PET), did not show any other involved site. The patient was diagnosed as having extranodal marginal zone B cell MALT-type lymphoma of the prostate, low grade and stage I. He received external beam radiation therapy to the prostate with a total dose of 44 Gy in 22 fractions. A follow-up biopsy of the prostate was performed 12 months after the radiation therapy. The immunohistochemical analysis showed no evidence of disease. He became free of disease within the following 24 months.