[Differential diagnosis of bluish red tumors of the posterior intact tympanic membrane].

Middle ear tumours may be seen frequently as bluish-red masses behind an intact tympanic membrane. In these cases all modern methods of visualisation such as CT or NMR are required for correct diagnosis and for planing adequate treatment. Most frequent are glomus tumours, either of the glomus tympanicum or the glomus jugulare. However, differential diagnosis must be considered, e.g. a tumour in the lower parts of the tympanon. In very rare cases the internal carotid artery takes an abnormal course, running free through the middle ear and touching the tympanic membrane. More often, granulomas or other inflammatory processes may be seen through a transparent ear drum. Haemangiomas or--of course--malignant tumours must be kept in mind. The role of modern radiographic methods is described in this paper, including some of the differential diagnoses mentioned above, with special reference to a case of carotid artery anomaly.