Wegener's granulomatosis is a multisystemic inflammatory illness of unknown etiology, characterized by vasculitis of small and medium caliber vessels. The most common clinical manifestations involve the upper respiratory tract, lungs and kidneys. Common alterations in imaging studies include pulmonary opacities and bilateral multiple nodules, cavitations occurring in 50% of the cases. Treatment includes corticosteroids and immunosuppressants. We describe an atypical case of a 61-year-old man initially investigated due to suspicion of a unilateral lung tumor, which proved to be, in fact, a case of Wegener's granulomatosis.

Keywords: Wegener's Granulomatosis; Vasculitis; Diagnosis, differential; Lung neoplasms.