Atypical vascular calcification with osseous and bone marrow metaplasia: post-mortem cases series with functional pathogenetic implications

Arterial vascular calcification is an ectopic mineralization similar to bone formation, acknowledged as an active process. Osseous metaplasia can be uncommonly observed inside vascular calcifications, mainly in the peripheral vessels, and rarely together with bone marrow cellularity, even if the incidence is underestimated. We hereby illustrate three cases, median age 82 years, female/male ratio 2/1, where osseous metaplasia with hematopoietic cells was incidentally observed within vascular calcifications: in one case in peripheral artery and in two cases in coronary arteries. Atherosclerosis and arterial hypertension were reported in the three cases. Final causes of death were pulmonary thromboembolism, myocardial infarction, and trauma due to car accident. Bone marrow metaplasia has important consequences for plaque stability, particularly in coronary arteries, because it could determine a risk per se of cardiovascular adverse events, but also a risk of adverse events in case of endovascular diagnostic or therapeutic procedures. Insight into the pathogenetic process and thus the possibility to assess the plaque rupture risk are of central importance for cardiovascular risk management.