Granulomatous prostatitis following Bacillus Calmette-Guérin therapy.

Granulomatous prostatitis (GP) is a rare form of chronic prostatitis with reported incidence of 0.65-1.5%. Radiological features of GP overlap with those of prostate adenocarcinoma. The following magnetic resonance imaging characteristics can suggest the diagnosis in an appropriate clinical setting: Diffuse or focal nodular low T2 signal, high signal on diffusion-weighted imaging with corresponding low apparent diffusion coefficient signal, and post-contrast imaging with lesion enhancement or rim-enhancing in the setting of caseous necrosis or abscess formation. Even with suspicion on imaging, the overlapping imaging features with prostate adenocarcinoma necessitate biopsy for confirmatory diagnosis. Here, we report a case of a 70-year-old man with GP in the setting of prior intravesicle bacillus Calmette-Guérin administration.