Which valve annulus is most commonly involved by caseous annular calcification?

• A. Aortic annulus
• B. Mitral annulus
• C. Tricuspid annulus
• D. Pulmonary annulus

Answer: (B)

Caseous annular calcification is a rare form of calcification that occurs specifically in the mitral annulus, forming a dense rim around a central, toothpaste-like material. It most commonly involves the posterior portion of the mitral annulus. That localization is what makes the mitral annulus the correct choice. Imaging often shows a calcified ring with a central lucent or low-attenuation area, which helps distinguish it from other entities such as abscess or tumor that can involve other valves. While calcification can occur around other valve annuli, the characteristic pattern and frequency point to the mitral annulus as the site most commonly involved.