Perineural Indentation by Benign Prostatic Glands

Benign prostatic glands may abut nerves. Occasionally, they may even partially wrap around a nerve. Complete encirclement of a nerve by prostatic glands (perineural invasion) is seen only in prostatic adenocarcinoma. It is a sufficiently specific finding that it alone may form the basis for the diagnosis of cancer. The nerve twig shown here is partially enclosed by glands that have a benign profile. They have large irregular lumens, lack enlarged nuclei or nucleoli, and show scattered basal cells.