Renal limited Wegener's granulomatosis.

Differential diagnosis in patients presenting with fever of unknown origin (FUO) is often difficult because infectious diseases, neoplasms, infective endocarditis or systemic autoimmune diseases may all be responsible for the condition. Furthermore, vasculitis may generate typical, atypical or limited syndromes depending on the extent of vascular involvement. Here, we report the case of a 73-year-old man with FUO and renal failure due to a rare variant of Wegener's granulomatosis, limited to the kidneys.