[Prostatic Lymphoma: a rare cause of urinary retention (a case report)].

Prostate lymphomas (LP) are rare, fewer than 300 cases have been reported in the literature. Each time they are a diagnostic surprise as is the case with our study that is typical, didactic and reports the thirteenth case of prostatic lymphoma in the marginal zone. The study involved a 65-year-old patient, with no particular previous history who presented with signs of prostatism lasting for 4 months, aggravated by the occurrence of acute urinary retention. The diagnosis of benign prostatic hyperplasia with normal prostate-specific antigen (PSA) level was easily made and the patient underwent transurethral resection. To our surprise, the histological study revealed a massive infiltration of prostatic tissue by a non-Hodgkin lymphoma (NHL), marginal zone lymphoma (MZL) subtype. According to Steuter, it was classified as prostatic lymphoma stage IVB with leukemic transformation. The patient has experienced remission for 18 months with normalization of LDH after R-chop therapy. Although rare, these sites of occurrence should be suspected, LDH assay should be systematic in patients with prostatic signs and normal PSA levels. Prognosis is variable, according to age, histologic type and evolutionary stage, however, the median overall survival is identical for primary and secondary forms.