[Abscess of the pyramidal apex].

The authors report on one case of an abscess at the pyramidal apex. The 52-year old male patient presented with pareses of the fifth and seventh cranial nerves and hypacusis on the right side. After diagnostic procedures (CT-scan, carotid angiography), a tumor at the apex of the right pyramid was expected. During surgery a large encapsulated mass was found containing pus. A bacterial agent could not be isolated. The abscess bordered on the mucosal lining of the sphenoid sinus and on the cells of mastoid bone. The starting point of an abscess at the pyramidal apex is most commonly an otitis media, most frequently caused by staphylococcus. Sterile abscesses are seen in almost 20%. Of differential diagnosis on has to keep in mind other space-occupying lesions especially epidermoid or dermoid cysts.