Osteoma of the Skull

• Benign mature osteogenic lesions
• Arise from membranous bones in the skull and face
• Highest incidence in 6^th decade
• Female to male ratio of 3:1
• Usually involve the frontal bone

Clinical Findings

• Asymptomatic
• Slow-growing, painless mass

Imaging Findings

• Rounded, sclerotic lesions usually arising from the outer table
• The diploe are spared
• Their borders are usually smooth
• The underlying cortex is not involved
• “Mature osteomas” may consist of a radiolucent nidus surrounded by  dense sclerosis (ivory osteoma)
• They have no Haversian canals and no fibrous component
• Trabecular osteomas are composed of cancellous bone surrounded by denser cortex
• Gardner Syndrome is multiple skull, sinus or mandible  osteomas associated with colon polyps and soft tissue skin tumors

Treatment

• Not needed unless for cosmetic reasons or from obstruction of a sinus producing mucocoele formation

 
Osteoma of the Skull. A smoothly marginated, very dense exostosis arises from the outer table of the occipital bone (red arrow) with an associated soft tissue mass.

P Bulloughs, Orthopaedic Pathologv (3rd edition), Times Mirror International Publishers Limited, London, 1997