Pseudotumor of urinary bladder.

The case of an old male is presented who had postoperative spindle cell nodule of urinary bladder. This benign condition mimics a sarcoma. However, the treatment modalities and the outcome are entirely different. Inflammatory pseudotumor/PSCN and leiomyosarcoma of the bladder overlap in clinical and immunohistochemical findings but are histologically as well as clinically distinct, correlating with different natural histories. Inflammatory Pseudotumor/PSCN are benign, not prone to metastasize, and is outside the spectrum of low-grade inflammatory sarcoma of urinary bladder.