Unusual growth of calcium lime with imbrication pattern in human coronary artery

Abstract

A 70 year old man was admitted to Hyogo Prefectural Amagasaki Hospital because of angina pectoris. Coronary angiography revealed a significant stenosis more than 90% at the proximity of the left anterior descending artery, to which directional coronary atherectomy was performed. The patient was not suffering from hypertension, diabetes mellitus, or hormonal disorders andhis renal function and serumcalcium concentration were normal. The atherectomy specimens contained abundant calcified lesions observed as black deposits in a preparation stainedwith von Kossa stain (Fig. 1B). Under an electronmicroscope, we observed small spherical calcium deposits (Fig. 2A) which are known to be usually observed in human atherosclerotic lesions [1]. Interestingly, we also noted an unusual growth of calcium lime in the extracellular matrix, showing “imbrication pattern” adjacent to collagen fibrils and cholesterol crystals (Fig. 2B to D). To our knowledge, such a pattern of calcium lime growth has not been reported in human coronary artery [2,3]. We are writing this letter to the editor and readers because we would like to know whether those strange lesions under an electron microscope are really uncommon in human coronary artery or common but have not simply been described and what is the specific etiology of such lesions, if any.