A 40 year old man presents with recurrent sinusitis for 2 years, associated with a bloody nasal discharge, intermittent cough and breathlessness. The response to antihistamines and antibiotics was poor. His medical and surgical histories are unremarkable and he is currently not on any medications. His full blood count shows a Hb level of 10.1 g/dL, and a leukocyte count of 13,500, with 85% neutrophils. His ESR is 110 mm in the first hour.
There is a nodular pulmonary lesion measuring ~3 cm in diameter in the upper lobe of the left lung. Multiple small nodular lesions are also seen in the right upper lobe. There is no evidence of hilar or mediastinal lymphadenopathy.
There is microscopic hematuria with red cell casts and proteinuria.
c-ANCA: elevated (1:64 titre) p-ANCA: negative Anti-GBM Abs: negative ANA, C3, C4: within normal ranges
Biopsy of lesion in the left upper lobe reveals granulomatous inflammation accompanied by an inflammatory infiltrate, vasculitis, and parenchymal necrosis.