Plasma cell infiltration of the urinary bladder.

We report a novel entity of plasma cell bladder infiltration without other demonstrable disease. The patient had severe irritative voiding symptoms, hematuria, and a diffuse mucosal infiltrate with 90% plasma cells. Although the patient demonstrated some clinical and pathologic evidence consistent with interstitial cystitis and eosinophilic cystitis, a predominant finding of focal plasma cell infiltration of the urinary bladder suggests a new or previously unrecognized clinical entity.