<prompt> 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 -Goodpasteurs syndromeClassic polyaeritis nodosaWegeners granulomatosisKawasaki syndrome  <response>: Ans. is c i.e., Wegeners granulomatosis o Renal and pulmonary symptoms with positive c-ANCA suggest the diagnosis of wegeners 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 Wegeners granulomatosis involves small vessels aeriole, venule, capillary, while PAN involves medium size vessels. o Wegeners granulomatosis is associated with c-ANCA, while classical PAN is not associated with ANCA. o In wegeners granulomatosis there is lung involvement, but not in classical PAN. o In wegeners granulomatosis there is glomerulonephritis hematuria without hypeension, while in classical PAN there is hypeension without glomerulonephritis. o In wegeners granulomatosis, there is granuloma formation, while it is absent in classical PAN. o Classical PAN shows microaneurysms which are absent in wegeners granulomatosis. Wegners granulomatosis Vs microscopic polyangitis o Wegeners granulomatosis is associated with c-ANCA, while MPA is associated with p-ANCA. o Granuloma formation occurs in wegeners granulomatosis, not in MPA. o Lung cavities and nodules are seen in wegeners granulomatosis, but not in MPA. 