IgG4-related prostatitis: a rare cause of steroid-responsive obstructive urinary symptoms.

IgG4-related disease is an idiopathic, systemic fibroinflammatory disease that can affect a wide variety of sites, including several in the genitourinary system. We describe a patient with steroid-responsive urinary symptoms and an abnormal digital rectal exam that were secondary to IgG4-related prostatitis. We discuss the importance of recognizing this condition and differentiating it from prostate cancer, which can present similarly.