[The mastoid osteoma, an incidental feature?].

Osteoma in the mastoid is a rare benign osteogenic tumour that has been described in literature in only 137 cases. It usually appears in asymptomatic patients, although a few cases are described associated with clinical manifestations. We report three cases of mastoid osteoma: a pedunculated osteoma in the aditus ad antrum (associated with a cholesteatoma), a superficial osteoma of the mastoid surface and a sessile osteoma that progressed to the temporal lobe (associated with vertigo). A brief review of this rare entity is presented and a possible association between mastoid osteoma, cholesteatoma otitis and vertigo is posed.