Rapid skeletal turnover in a radiographic mimic of osteopetrosis.

Among the high bone mass disorders, the osteopetroses reflect osteoclast failure that prevents skeletal resorption and turnover, leading to reduced bone growth and modeling and characteristic histopathological and radiographic findings. We report an 11-year-old boy with a new syndrome that radiographically mimics osteopetrosis (OPT), but features rapid skeletal turnover. He presented at age 21 months with a parasellar, osteoclast-rich giant cell granuloma.

Thyrotoxicosis after matched unrelated bone marrow transplantation.

Acquired hyperthyroidism is most commonly autoimmune in etiology. In the setting of allogeneic bone marrow transplantation (BMT), the use of radiotherapy (total body irradiation) as part of the regimen prior to BMT is known to cause endocrine dysfunction, especially hypopituitarism and hypothyroidism, but hyperthyroidism is rare. The authors report this unusual and late complication in a young boy after BMT for relapsed childhood lymphoblastic leukemia and discuss the possible etiologies.