Paraganglion of the prostate in a needle biopsy: a potential diagnostic pitfall.

Paraganglionic tissue incidentally observed in a needle biopsy of the prostate is reported. The tissue was seen in the periprostatic adipose tissue obtained during a needle biopsy of the prostate of an 81-year-old man. The paraganglionic cells demonstrated round to oval nuclei and basophilic granular or vacuolated cytoplasm and were immunohistochemically positive for chromogranin A, but negative for prostatic acid phosphatase and prostate-specific antigen. Paraganglion in the periprostatic adipose tissue is a diagnostic pitfall and should be distinguished from extension of prostatic adenocarcinoma outside the prostatic capsule into the periprostatic adipose tissue.