《Slide 54.》Endocardial fibroelastosis, Heart
A. Brief Descriptions：
Focal to diffuse, cartilage-like fibroelastic thickening of the endocardium.
LV more often than RV,commonly under 2 y/o,congenital cardiac anomalies present in 1/3 of the cases.
Theories of etiology : hypoxia,congenital, ...etc.
B. Gross Findings：
Diffuse or patchy fibroelastic thickening of the endocardium,mostly on the left,occasionly with overlying mural thrombi.
Cardiomegaly due to LV hypertrophy and or dilation.
C. Micro Finding：
Endocardial thickening due to marked increase of collagenous and elastic fibers.
Fibroelastic layer extends into the immediate subjacent myocardium.
Robbins Pathologic Basis of Disease, 6th ed. P.584.
【 Fig. 54-1 (LP)】Patch of fibroelastic thickening of endocardium (right).
【 Fig. 54-2 (LP)】Patch of fibroelastic thickening of endocardium extending into myocardium. (right lower corner).
【 Fig. 54-3 (HP)】Fibroelastic endocardium with increase of collagenous and elastic fibers; note residual myocardial muscle bundles in the left side of the picture.