Postoperative spindle cell nodule of the prostate and bladder.

Postoperative spindle cell nodule of the prostate and bladder (a rare lesion often misinterpreted as sarcoma) is important to recognize. The nodule consists of a reactive proliferation of spindle cells occurring up to several months after a lower genitourinary tract procedure, such as transurethral resection or biopsy. We report on 5 patients with a spindle cell nodule after a prior operation on the prostate or bladder. Of these patients 2 initially were diagnosed as having leiomyosarcoma, including 1 who underwent radical cystoprostatectomy. Because of the potential for inappropriate treatment the clinician must be aware of this entity so that he might question the diagnosis and raise the possibility of a postoperative spindle cell nodule whenever sarcoma is diagnosed after recent surgical instrumentation for a nonmesenchymal lesion in the genitourinary tract.