Primary mastoid cyst

To report an unusual case of a primary mastoid cyst (congenital or developmental) in a patient without otological symptoms. Case report and review of the English language literature. Primary mastoid cyst is a newly reported and very rare pathological entity. Mastoid cysts usually occur secondary to chronic infection, inflammation or trauma. Review of the medical literature highlights the rarity of this condition. This report describes the experience gained by the diagnosis and management of this patient. It emphasises the importance of clinical vigilance so that proper treatment may be instituted in a timely manner.