Leontiasis ossea: a paleopathologic case report.

We describe the archeological and imaging findings of a unique specimen (skull and mandible) with leontiasis ossea (LO) that is on display in the National Museum of Anthropology and History in Mexico City. The specimen shows diffuse and irregular periosteal bone proliferation, which produces a grossly nodular appearance involving the neurocranium and the facial skeleton. Plain radiography and helical computed tomography revealed generalized hyperostosis obliterating the maxillary and sphenoidal sinuses and 2 exuberant bony masses arising from the maxilla with encroachment of the anterior nasal aperture.Currently, LO is a purely descriptive term applied to a variety of osseous conditions that have in common hyperostosis of craniofacial bones leading to a leonine appearance. Clinicians who see such lionlike facies should consider the main causes of LO, which include renal osteodystrophy, Paget disease and, as most likely in this specimen, fibrous dysplasia.