Uremic leontiasis ossea: "bighead" disease in humans? Radiologic, clinical, and pathologic features.

PURPOSE

To describe the clinical, radiologic, and pathologic findings in patients with uremic leontiasis ossea (ULO).

MATERIALS AND METHODS

Five patients with renal osteodystrophy developed marked hyperostosis of the facial and cranial bones. Radiologic studies included plain radiography of the skull (n = 5), computed tomography with three-dimensional reconstruction (n = 4), magnetic resonance imaging (n = 3), and fluorine-18 sodium fluoride positron emission tomography (PET) (n = 1). Specimens from bone biopsies (three patients) were examined.

RESULTS

Skull and facial alterations were remarkably similar. Numerous nodules of varying attenuation and signal intensity in the widened diploic space suggested brown tumors in different stages of evolution. Biochemical data and PET findings enabled confirmation of markedly increased bone turnover. Bone specimens demonstrated severe osteitis fibrosa. After parathyroidectomy, facial changes in all patients stabilized or improved mildly.

CONCLUSION

A similar entity in animals, "bighead" disease, which results from nutritional and uremic secondary hyperparathyroidism, may provide a useful animal model for ULO in humans. Mild forms of this entity may be more common than the scarcity of previous reports suggests.