Cartilaginous and osseous metaplasia with bone marrow formation in the aortic valve of a patient with giant cell aortitis

We describe the case of a 40-year-old man who presented with an ascending aortic aneurysm and aortic valve regurgitation. The patient underwent a Bentall surgical procedure. Pathologic findings were consistent with giant cell aortitis with synchronous cartilaginous and osseous metaplasia with bone marrow formation in the degenerated aortic valve. The coexistence of these findings has not been previously reported in the English language literature.