Giant cell arteritis detected by bone marrow biopsy.

A case of giant cell arteritis is reported that was detected by bone marrow biopsy. The histopathologic features of the bone marrow lesion included an enlarged artery, whose wall showed intimal thickening, fibrinoid necrosis, destruction of the internal elastic lamina, and multinucleated giant cells. The demonstration of involvement of bone marrow vessels by giant cell arteritis reaffirms the systemic nature of the disease. Bone marrow biopsy is not the method of choice for establishment of the diagnosis of giant cell arteritis, but it may lead to the diagnosis in rare instances.