Osteosclerosis, osteomalacia, and bone marrow aplasia: A combined late complication of thorotrast administration

A 37-year-old female with thrombocytopenia since childhood developed diffuse osteosclerosis followed by bone marrow aplasia 23 years after Thorotrast administration. Tissue deposition of Thorotrast was documented by radiospectroscopy (liver, bone) and autoradiography (bone). Bone marrow failure in this patient was clinically ascribed to diffuse myelofibrosis, but at autopsy marrow fibrosis was only focal. An unsuspected bone mineralization defect was manifested by thick osteoid seams. It is suggested that osteosclerosis, osteomalacia, and bone marrow aplasia represent a combined experession of Thorotrast cytotoxicity.