Patterns of inflammation in prostatic hyperplasia: a histologic and bacteriologic study.

In a series of 162 cases of surgically resected hyperplastic prostates the incidence of inflammation is 98.1%. Six morphologic patterns of inflammation are described: 1) segregated glandular inflammation, 2) periglandular inflammation, 3) diffuse stromal inflammation, 4) isolated stromal lymphoid nodules, 5) acute necrotizing inflammation and 6) focal granulomatous inflammation. The most common pattern, segregated glandular inflammation, is characterized by intraluminal neutrophils and foamy macrophages and by chronic inflammatory cells in the surrounding stroma. No significant morphological differences are found among groups of cases with positive and negative evidence by culture of bacterial prostatic infection. Quantitative but not qualitative morphologic differences are found between cases of gram-negative infections and infection by gram-positive organisms that often are considered non-pathogens.