[Hyperostosis frontalis interna : etiology and differential diagnosis].

Hyperostosis frontalis interna was first described in 1719 in association with obesity and hirsutism, forming Morgagni's syndrome. A high prevalence and a lack of studies demonstrating a strong correlation between these different signs currently question the existence of such a syndrome. Hyperostosis frontalis interna predominates in women. The anomaly exclusively involves the inner table and constantly spares the diploe and the external table. The main differential diagnosis of cranial hyperostosis is made between meningioma, osteoma, Paget's disease and fibrous dysplasia. The clinical implication of hyperostosis as well as its etiology are also debated.