Malignant tumors in the middle ear and mastoid are very rare. Of these very uncommon tumors, the squamous cell cancers are the most common. Squamous cell cancer of the middle ear and mastoid is a fatal disease, if not treated properly. These cancers are usually found in individuals who have neglected chronic infection in the mastoid or middle ear. The exact relationship of the infection to the formation of the squamous cell cancer is unclear. Presumably, it is related to chronic inflammation.
Malignant tumors of the mastoid and middle ear accounts for 5 to 26% of all ear neoplasms. Of these neoplasms, squamous cell carcinoma is the most common, with an age-adjusted incidence of 1 case in 1 million and peak age of 60 years.
Squamous cell cancer of the middle ear is often quite advanced before a correct diagnosis is made. Pain is a significant feature of squamous cell cancer of the middle ear and mastoid. Intermittent hemorrhage, bleeding and drainage for long periods of time are also usual. Hearing loss is significant. Diagnosis depends upon a biopsy of the tissue.
The major etiological factor is chronic suppurative otitis media although irradiation and inverted papilloma of the middle ear have also been reported to be additional risk factors.
Human papilloma virus types 16 and 18 have been associated with squamous cell carcinoma of the middle ear at both tissue and molecular levels, thus providing a good model to explain the pathogenesis of chronic inflammation-related human malignancies.
An examination by the ear surgeon investigating a perforated eardrum which shows suspicious tissue in the middle ear or mastoid that does not heal after appropriate medical therapy would indicate a need for a biopsy. Suspicion should be aroused about any unusual tissue which is seen through a perforated eardrum or mastoid, particularly those that are painful. After topical or local anesthesia is placed into the ear, the tissue to be biopsied is sent off for analysis and a pathologist will be able to determine whether cancer is present in the tissues. During middle ear mastoid surgery any polyps or granulations seen must be sent for histopathology as routine.
CT scan and MRI are necessary in order to help determine the extent of surgery necessary. Even with early surgery and radiation therapy, cure may not be possible if the tumor is deeply invasive. Thus, it is imperative that diagnosis be made as early as possible. Once diagnosis is made, the patient must be prepared for radical surgery.
Glomus tumors are the most common benign tumors of the middle ear. They arise from glomus bodies. Glomus bodies are tiny, normal structures in the middle ear which serve as baro receptors. These baro receptors sense and help to regulate the oxygen pressure in the middle ear and mastoid.
Benign tumors of glomus bodies can occur within the middle ear or at other sites: the temporal bone and neck, or within the jugular vein (the large vein in the upper neck which drains the head toward the heart). Glomus tumors of the middle ear are more common than glomus tumors of the jugular vein. They can result from abnormal growth of a single glomus body.
Glomus tumors are highly vascular and are primarily composed of blood channels flowing through the tumor itself. They appear red on examination of the eardrum. Most glomus tumors are readily noted by an n ENT Surgeon\’s routine examination of the ear. They appear as a red ball or mass behind the eardrum. The eardrum may pulsate, if the glomus tumor is touching the under surface of the intact eardrum.
Diagnostic Imaging Studies
CT scan: CT scanning of the mastoid and middle ear determine the extent of bone involvement. As a tumor grows, it will invade and destroy bones. Cancers also appear on a CT scan, and an estimate of the extent of the disease can be obtained.
MRI scanning can demonstrate the infiltration of the tumor into soft tissue, specifically tissue in the front of the ear or parotid gland area. MRI will also help to determine if the tumor has invaded the dura, which is the capsule surrounding the brain. If the tumor has grown through the plate of bone that separates the middle ear and mastoid from the brain, then cure becomes quite difficult.
The classical treatment is combined surgery and radiotherapy, although either method may be used alone. Most authorities agree that a combination of surgery and radiotherapy as opposed to single modality treatment is likely to yield the best results.
Glomus tumors are not highly radiosensitive. However, in older patients, or those who should not undergo sugery, radiation therapy may help to arrest the growth of a glomus tumor. In the younger patient, complete surgical removal of the tumor after emobilzation is the preferred method of treatment.