Granulomatous prostatitis: a spectrum including nonspecific, infectious, and spindle cell lesions

Most granulomas of the prostate are nonspecific; infectious, post-operative, and allergic lesions are much less common. Fine-needle aspiration findings in the typical case are distinctive and easily recognized. Several series have been reported, but few have included histologic follow-up. We describe three cases of granulomatous prostatitis (GP) which showed a spectrum of findings confirmed by histologic sections. In all cases, carcinoma was suspected clinically. Case 1 represents typical nonspecific GP with epithelioid and multinucleated histiocytes. In case 2, aggregates of epithelioid histiocytes alternated with areas of necrosis and neutrophils. Histologically, the granulomas showed purulent centers. Silver stains revealed budding yeast in smears and sections. Cultures of FNA material subsequently revealed Cryptococcus. In case 3, the histiocytes were predominantly spindled and occurred singly and in groups. The differential diagnosis included reactive and neoplastic spindle cell lesions. Histologic sections showed GP with spindled histiocytes. Appreciation of the broad cytologic spectrum of GP will facilitate accurate cytologic diagnosis.