UREMIC LEONTIASIS OSSEA - BIGHEAD DISEASE IN HUMANS - RADIOLOGIC, CLINICAL, AND PATHOLOGICAL 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 hyperostosi s of the facial. and cranial bones. Radiologic studies included plain radiography of the skull (n = 5), computed tomography with three-dimen sional 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. RESULT S: Skull and facial alterations were remarkably similar. Numerous nodu les of varying attenuation and signal intensity in the widened diploic space suggested brown tumors in different stages of evolution. Bioche mical data and PET findings enabled confirmation of markedly increased bone turnover. Bone specimens demonstrated severe osteitis fibrosa. A fter parathyroidectomy, facial changes in all patients stabilized or i mproved mildly. CONCLUSION: A similar entity in animals, ''bighead'' d isease, which results from nutritional and uremic secondary hyperparat hyroidism, may provide a useful animal model for ULO in humans. Mild f orms of this entity may be more common than the scarcity of previous r eports suggests.