Mesonephric Remnant of the Prostate

Definition

Proliferation of benign acini arranged in lobules or infiltrating between muscle bundles and prostatic acini without a stromal desmoplastic response (Bostwick et al. 2003; Chen et al. 2011).

Clinical Features

• Incidence

  Present in <1% of transurethral resections and are rarely identified in needle biopsies.

• Age

  Patients ranged in age from 66 to 82 years (mean, 72 years).

• Sex

  Male.

• Site

  Prostate.

• Treatment

  Not required.

• Outcome

  Benign not associated with increased risk of cancer.

Microscopy

Histologically mesonephric remnants are identical to what is seen in the female genital tract, being composed of small glandular structures lined by a single layer of cuboidal cells, with scant amounts of eosinophilic or amphophilic cytoplasm, usually with dense eosinophilic colloid-like intraluminal secretory material (Fig. 1) (Bostwick et al. 2003). In some cases, they are forming glands with papillary infoldings or micropapillary tufts or ill-formed small glands intermixed with spindle...