The Management of Carcinoma of the Middle Ear

Carcinoma of the middle ear is rare, arising in association with chronic suppuration. It may begin in the altered epithelium of the middle ear, in the mastoid air cells, or deep in the external auditory meatus and, with a ruptured tympanic membrane, finds no difficulty in spreading to the middle ear (1). Cases of carcinoma of the external auditory canal which are limited to the canal are not included in this discussion. For a time the disease is confined by the bone which it later invades and has a tendency to spread into the middle cranial fossa. By more superficial extension, it perforates the cartilaginous canal and spreads on the exterior surface of the skull. The patient presents with an exacerbation of his discharge which may be blood-stained, or with continuous deep boring pain from bone invasion, or with facial paralysis. The lymph nodes in the neck become involved, and finally, if the patient survives, uncured, distant metastases to the liver and lung become apparent. The diagnostic problem is one of the extent of the disease, because a small granulating lesion in the middle ear may look confined but in reality be of considerable extent. A full radiologic study of the base of the skull is necessary. The therapeutic problem is twofold: first, the disease originates in the middle of the densest bone in the body and is thus shielded from any attempt at external radiation; second, the point of origin is 4 cm. from the medulla oblongata and pons. At the Christie Hospital, Manchester, England, between 1932 and 1949, of 56 cases there was survival in only 8, or 15 per cent. In the management of these early cases, however, five lessons were learned (2): 1. There should be no surgical interference other than biopsy before the irradiation is begun. Death occurred in all the 10 cases with a pre-irradiation mastoidectomy. 2. Intracavitary methods of radium insertion are theoretically unsatisfactory and in practice yield poor results. 3. External irradiation offers a hope of cure by the use of multiple small-field beam-directed x-rays. 4. The dose of 250-kv x-ray can be too high, and 5,000 r in three weeks is preferable to a dose of 5,500. 5. Brain stem damage begins when the midbrain is irradiated to a dose of 5,000 r in three weeks. If this is exceeded, a significant number of patients succumb from transverse myelitis. The solution to these problems lies in the use of a hard quality of radiation and in treatment planning to avoid full-dose irradiation of the brain stem. Before the 4-Mev linear accelerator was available in Manchester, 11 cases were treated by a radium beam cluster with a supplementary dose of intracavitary radium in the middle ear. With this method the hard quality of irradiation was provided and the medulla was avoided but the area to which a full dose could be delivered was restricted. A more satisfactory dosage distribution is obtained by three fields of 4 Mev x-rays.