<prompt> 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 -Goodpasteurs syndromeClassic polyaeritis nodosaWegeners granulomatosisKawasaki syndrome  <response>: Ans. is c i.e., Wegeners granulomatosiso 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 PANo 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 polyangitiso 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. 