The radiology of carcinoma of the ear

Carcinoma arising in external auditory meatus, middle ear cleft or mastoid cavity has a poor prognosis unless treated at an early stage. Biopsy of any suspicious tissue is the key to early diagnosis but there are radiological features which may suggest the presence of a malignant neoplasm. An important role of radiology is the demonstration of the extent of disease and of spread beyond the confines of the temporal bone. The optimum regime of surgery and radiotherapy cannot be planned without this information. The radiological features of 47 aural carcinomas were reviewed. Thirty-two of the cases were examined by multidirectional tomography and six by computed tomography. The modes of spread of the neoplasm are discussed as well as the differential diagnosis. It is concluded that high resolution CT is now the optimum method of demonstrating tumour spread in the axial plane and frequently also in the coronal section. Lateral tomograms are necessary to show erosion of the walls of the external auditory meatus. Erosion of the bony septum separating the middle ear cavity from the carotid canal can be shown on coronal sections and is an important sign of spread anteriorly. Soft tissue extension into the infratemporal fossa may be demonstrated by high resolution CT.