A patient presents with respiratory symptoms i.e. cough, hemoptysis and glomerulonephritis. His CANCA levies in serum were found to be raised. The most likely diagnosis is -

Ans. is 'c' i.e., Wegener's granulomatosiso Renal and pulmonary symptoms with positive c-ANCA suggest the diagnosis of wegener's glomerulonephritis (see above explanation).o Clinical syndrome of wegener granulomatosis may be very similar to classical PAN or microscopic polyangitis. Following facts will help you to differentiate wegner granulomatosis from other Two ?Wegeners granulomatosis Vs classical PANo Wegener's granulomatosis involves small vessels (aeriole, venule, capillary), while PAN involves medium size vessels.o Wegener's granulomatosis is associated with c-ANCA, while classical PAN is not associated with ANCA. o In wegener's granulomatosis there is lung involvement, but not in classical PAN.o In wegener's granulomatosis there is glomerulonephritis (hematuria) without hypeension, while in classical PAN there is hypeension without glomerulonephritis.o In wegener's granulomatosis, there is granuloma formation, while it is absent in classical PAN. o Classical PAN shows microaneurysms which are absent in wegener's granulomatosis.Wegner's granulomatosis Vs microscopic polyangitiso Wegener's granulomatosis is associated with c-ANCA, while MPA is associated with p-ANCA. o Granuloma formation occurs in wegener's granulomatosis, not in MPA.o Lung cavities and nodules are seen in wegener's granulomatosis, but not in MPA.