Pseudosarcomatous lesions of the urinary bladder, prostate gland, and urethra. A report of three cases and review of the literature.

Three pseudosarcomatous lesions of the genitourinary tract are described. One that arose in the urinary bladder of a 59-year-old man was composed of atypical spindle cells admixed with inflammatory cells in an edematous stroma. The second lesion occurred in the stroma of a hyperplastic prostate gland of a 51-year-old man and was characterized by the presence of numerous atypical mesenchymal cells with large, hyperchromatic nuclei. The third case was that of a 57-year-old woman with a urethral caruncle that contained numerous atypical mesenchymal cells in its stroma. All three patients were treated conservatively, and follow-up for periods ranging from 18 months to eight years has revealed no evidence of recurrence. Knowledge of the various atypical mesenchymal cell proliferations that are encountered in the genitourinary tract may prevent the misdiagnosis of a malignant tumor.