Granulomatous prostatitis: a clinicopathological study.

In a clinicopathological study of granulomatous prostatitis, we have found two distinct histological patterns. Approximately one third of cases consisted of localized, often elongated or stellate lesions, resembling rheumatoid nodules. Where clinical details were available, most of these cases had a history of previous transurethral resection. The remaining cases showed more diffuse involvement of the prostate, with lesions centred on ducts and glands, and were not associated with previous prostatic surgery or systemic illness. Immunohistochemical studies of the associated inflammatory infiltrate showed an apparently random distribution of T- and B-lymphocytes in the former group, while in the latter group there was a concentration of T-cells in and around damaged ducts and glands, suggesting a possible immune-mediated destruction of these structures.