Caseous Calcification: Now You See Me, Now You Don't.

Caseous calcification of mitral annulus is a rare variant of mitral annulus calcification that can mimic infective endocarditis, myocardial abscess, valve myxoma, or papillary fibroelastoma. On transthoracic echocardiography, the mass appears as a large, round echodense structure with a large calcification and central echolucency. We present a case of a 72-year-old female with a past medical history significant for diabetes mellitus, hypertension, and end-stage renal disease who was noted to have caseous calcification of the mitral annulus on transthoracic echocardiography, which was done as part of a preoperative kidney transplantation evaluation. The mass spontaneously resolved before the planned mitral valve surgery. Caseous calcification of mitral annulus should be considered in the differential for a cardiac mass, particularly if it is attached to the posterior aspect of the mitral valve. Accurate identification of this rare cardiac mass is essential to avoid unnecessary surgical intervention as clinical course is usually benign.