Lis 3898_r1.qxd:Layout 1

Ectopic valvular ossification during the course of degenerative valve disease is a relatively rare event. The presence of lamellar bone tissue in human cardiac valve was first documented histologically by Rosenstein over a century ago (1). The frequency of ossification in surgically excised native cardiac valves reported in three large retrospective analyses was 13% (aortic and mitral valves) (2), 10.9% (aortic and mitral valves) (3), and 4.4% (aortic valves) (4), while the prevalent pathology calcification was found in over 80% of valves. Although calcification occurs frequently in implanted valve homografts, advanced ectopic ossification has not been reported thus far. Herein is presented a case where, for the first time, mature lamellar bone with hematopoietic elements was identified in an aortic valve homograft.