Imaging appearance of granulomatous disease after intravesical Bacille Calmette-Guerin (BCG) treatment of bladder carcinoma

Abstract

Editorial CommentOn MR imaging, most renal masses are hypointense on T1 and hyperintense on T2, thus comparison between T1-weighted image pre and post intravenous injection of contrast readily shows variable degree of hyperintensity of the lesions due to contrast enhancement (particularly hypervascular ones). Some lesions, however, are hyperintense in T1-weighted images making the perception of contrast enhancement a very difficult task. These hyperintense lesions on T1-weighted images are either benign (hemorrhagic cyst, hematoma, vascular lesion or oncocitoma) or malignant masses (papillary renal cell carcinoma). Image subtraction technique is very useful for the demonstration of subtle contrast enhancement in hyperintense T1 lesions. Image subtraction however can be of limited value in patients with irregular respiratory movements, which precludes adequate images subtraction.DW imaging has been used to assess several renal disorders: infection, ischemia, obstruction and masses. The authors of this manuscript show that DW imaging can be of value to characterize non-fat-containing T1 hyperintense lesions. They found that the diffusion is more restricted in renal cell carcinoma (lower ADC values) than in benign hemorrhagic or proteinaceous cyst. Although with lower sensitivity than that image subtraction, the authors recommend DW imaging as an alternative to contrast-enhanced MRI in patients with chronic renal insufficiency that are at risk for development of nephrogenic system fibrosis secondary or associated with gadolinium-containing agent. Dr. Adilson PrandoChief, Department of Radiology and Diagnostic Imaging, Vera Cruz Hospital Campinas, São Paulo, Brazil E-mail: adilson.prando@gmail.com Imaging appearance of granulomatous disease after intravesical Bacille Calmette-Guerin (BCG) treatment of bladder carcinomaMa W, Kang SK, Hricak H, Gerst SR, Zhang J Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA AJR Am J Roentgenol. 2009; 192: 1494-500 Objective: The purpose of our study is to present the radiographic findings in a series of 16 patients with complications associated with intravesical bacille Calmette-Guérin (BCG) treatment of bladder cancer. Conclusion: Intravesical BCG-related complications such as granulomatous disease may show imaging findings mimicking primary or metastatic tumors in patients with bladder cancer. Radiologists should consider this possibility when imaging abnormalities are encountered in bladder cancer patients treated with intravesical BCG so that appropriate management can be administered and unnecessary procedures avoided. Editorial CommentIntravesical therapy with bacillus Calmette-Guérin (BCG) has proved to be more effective in the prophylaxis and treatment of superficial bladder tumors and carcinoma in situ than most chemotherapeutic agents. Some complications however may occur with this treatment. Granulomatous reaction may occur either in the urinary tract or sporadically outside the urinary tract (hepatitis, disseminated infection...