Benign and Malignant Prostatic Urethral Polyps: Two Case Reports and Review of Literature

Abstract

Polypoid mass in the prostatic urethra is uncommon, yet the disease entities are so heterogeneous that the spectrum ranges from congenital malformations, benign polyps, to various malignancies. Prostatic urethral polyp (PUP) is a rare benign overgrowth of prostatic parenchyma protruding into prostatic urethra, and correspondingly, prostatic ductal carcinoma is a rare carcinoma originated from the primary duct of the prostate and occasionally presents as a polyp in the prostatic urethra.  Due to the location of the polyps, varieties of symptoms, including dysuria, hematuria, urinary tract infections and obstruction leading to urinary retention, can be encountered and diagnostic confusion might be appreciated.  Here we report two cases of polypoid mass located in the prostatic urethra: one case of benign PUP and another one of malignant prostatic ductal carcinoma protruding into prostatic urethra.  The origins of both lesions were proven to be prostatic epithelium by using immunohistochemical identification of prostate-specific antigen (PSA).  Further histological and immunohistochemical studies established the diagnoses of PUP and prostatic ductal carcinoma respectively.  Their mimickers, including prostatic acinar adenocarcinoma, villous adenoma of urinary bladder, and papillary urothelial cell carcinoma, were also reviewed.