Caseous Peripheral Medial Arterial Calcification With Inflammation and Luminal Occlusion

Caseous calcification is a rare form of calcification characterized by liquefactive degeneration into amorphous, cheese-like material. Although well recognized in mitral annular calcification, it has not been reported in peripheral arteries.

A 51-year-old man with end-stage renal disease on peritoneal dialysis developed chronic limb-threatening ischemia requiring below-the-knee amputation despite revascularization. Radiography, micro-computed tomography, and histology of the anterior tibial artery demonstrated focal caseous calcification within extensive medial calcification. Unlike sheet-like calcification with minimal inflammation, caseous lesions were associated with numerous multinucleated giant cells, macrophages, and T lymphocytes, as well as thrombus formation, severe luminal narrowing, and focal chronic total occlusion.

This case provides the first histopathological evidence of peripheral arterial caseous calcification associated with severe inflammatory response and luminal occlusion.

Caseous calcification may represent a distinct inflammatory phenotype of medial arterial calcification that contributes to luminal narrowing and thrombosis in the absence of atherosclerosis.