Mastoid pneumocele with secondary pneumatocele causing external auditory canal obstruction and the influence of forced nose blowing.

We present a case involving a 36-year old man who had a feeling that his right ear was obstructed and who had associated conductive hearing loss that was exacerbated by nose blowing. On otoscopy, a soft-tissue swelling was seen in the posterosuperior aspect of the right external auditory canal. Computed tomography revealed the presence of hyperaerated mastoid air cells and air-containing cavicy connected with the enlarged mastoid air cells, narrowing the external auditory canal. A radiographic diagnosis of mastoid pneumocele with secondary pneumatocele was made. A novel hypothesis is presented, that high nasal pressures play an important role in the progressive formation of pneumocele/pneumatocele as a result of air invasion via the eustachian tube. Symptoms disappeared after a myringotomy was placed. Computed tomography performed 6 months later showed an impressive remodeling of the temporal bone.