Mc-Callum's patch is diagnostic of -

(B) (Rheumatic endocarditis) (Robbin's 8th edpg. 566)Pathological features of Rheumatic carditis1. Acute Rheumatic carditisThere is diffuse inflammation and aschoff bodies in any of the three layers of heart - pancarditisa) Pericardium - Fibrinous or serofibrinous pericarditis also known as "bread and butter" pericarditis. Pericarditis generally resolve without sequelae.b) Myocardium - Diffuse non-specific myocarditis with Aschoff bodies.c) Endocardium - Small warty projections, i.e. verucae along the line of closure on the valvular leaflets (especially on left side mitral valve).2. Chronic rheumatic carditis* Chronic RHD is characterized by organization of the acute inflammation and subsequent fibrosis.* In particular, the valvular leaflets becomes involved and characterized by-- Leaflet thickening- Commissural fusion- Shortening, thickening and fusion of chordae tendinae.* Fibrous bridging across the valvular commissures and calcification create "fish mouth" or''Buttonhole" stenosis.* Mitral valve is involved most commonly.* RHD is the most common cause of mitral stenosis.* Aortic valve is second commonest valve to involve.* Tricuspid valve may also be involved.* Irrigular thickening of the posterior wall of left artrium - MacCallum plaque.* MacCallum plaque is due to subendothelial collection of Aschoff nodules.* Most frequent cardiac tumour for all age group is metastasis* Most frequent primary cardiac tumor - Myxoma.* Most frequent primary cardiac tumour in infants and children is Rhabdomyoma.