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

Ans. is 'c' i.e., Wegener's granulomatosis o 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 PAN o 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 polyangitis o 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.