P. acnes-positive glands and P. acnes-positive macrophages in the negative prostatic needle biopsy samples detected by IHC with PAL antibody.

Two representative areas with many P. acnes-positive glands or P. acnes-positive macrophages are shown pairwise (A-B or C-D, respectively) with hematoxylin and eosin staining (A, C) and IHC with the PAL antibody (B, D). A-B: Many P. acnes-positive glands are clustered in an area of the first negative biopsy sample from a patient with PCa. The antibody reacted with a few small round bodies in some epithelial cells, as shown in the inset, of the gland indicated by an arrow. C-D: P. acnes-positive macrophages are clustered in some areas of stromal inflammatory cell infiltration of the first negative biopsy samples from a patient with PCa. The antibody reacted with many small round bodies, as shown in the inset, of the macrophages indicated by an arrow.