A 40-year-old woman presents with bilateral conductive hearing loss, palpable purpura on the legs and hemoptysis. CT scan of the chest shows few thin-walled lung cavities bilaterally. Fuher investigations reveal total leukocyte count 12,000/mm3, red cell casts in the urine and, serum creatinine 2.3 mg/dL. What is the most probable diagnosis?

Wegener's granulomatosis: Granulomatosis with polyangiitis (GPA), previously known asWegener granulomatosis, is a multisystem necrotizing non-caseating granulomatous c-ANCA positive vasculitis affecting small to medium-sized aeries, capillaries, and veins, with a predilection for the respiratory system and kidneys. Figure: Multiple thick walled cavitating lesions in both lungs. On CT, a feeding vessel leading to nodules and air bronchogram on it may be seen. Linear bands, spiculations and pleural tags may also be seen in the relation. Cavitation is characteristic of it. Consolidation and groundglass opacities are also recognized features.