Gofrit ON et al (2007). Significance of inflammatory pseudotumors in patients with a history of bladder cancer. Urology 69: 1064–1067

Carcinomas or sarcomas of the bladder are uncommonly associated with lesions composed of proliferating fibroblasts and inflammatory filtrate, known as inflammatory pseudotumors (IPT). These lesions occur either spontaneously or after surgical trauma. In this study, Gofrit et al. investigated the significance of IPT found in patients after resection of bladder cancer.

The authors used the hospital database to identify patients who had a history of bladder cancer and were treated with transurethral resection, had a bladder mass that was discovered during routine follow-up and histologic evidence of an IPT in the removed tissue. Of 919 patients treated for bladder cancer between 1988 and 2005, a total of 809 patients were at risk for developing IPT. The original slides of the primary bladder tumors were reviewed and stained for pancytokeratin, anaplastic large cell lymphoma and vimentin.

IPTs developed in 16 patients (2%) during follow-up. The primary tumor was a high-grade transitional cell carcinoma in all patients. In all cases, staining for vimentin was positive and anaplastic large cell lymphoma was negative. In two patients, staining for pancytokeratin was positive. After a median follow-up of 16 months, 12 patients developed tumor recurrence. The median time to progression from diagnosis of IPT was 7 months, and nine patients had tumor progression. After a median time of 26 months from diagnosis of IPT, six patients died.

The findings of this study suggest that the occurrence of IPT in patients with a history of bladder cancer is commonly associated with aggressive malignant disease.