Tumors of the Middle Ear & Mastoid

Related terms:

Tumors of the ear can be benign or malignant. They can occur on the external ear, or in the ear canal, the middle ear or inner ear. Tumors in different areas of the ear behave differently. Thus, it is necessary to describe tumors based on their site of occurrence, as well as their behavior and treatment.

Tumors of the Middle Ear

Polyps and Granulation Tissue of the Middle Ear: Polyps can develop in the middle ear. As such, these are not necessarily benign tumors. They look like balls of inflamed tissue which form grape-like clusters within the confines of the middle ear and mastoid. These polyps generally are reddish and bleed easily on vacuuming or any manipulation. They may be indistinguishable from more serious problems of the middle ear and mastoid. If they do not respond to medical therapy, polyps should be biopsied. In most cases of advanced polyps and inflammation of the middle ear, surgery of the middle ear and mastoid will necessary.

Cholesteatoma: These are tumors of the middle ear which are usually benign and the most common of all middle ear tumors. These are dealt with fully in a separate section, “Cholesteatoma.” Cholesteatoma arises from a perforation of the tympanic membrane with ingrowth of skin into the middle ear. Also, they appear congenitally from an epidermoid formation which is also described in the “Recent Research” section. Full information on these topics can found in this web site.

Less Common Benign Tumors of the Middle Ear

Facial Nerve Neuroma

One of the less common benign tumors of the middle ear is the facial neuroma, a tumor of the facial nerve. As it expands, it can put pressure on the facial nerve and cause facial paralysis. These tumors are clinically important.

Excision of the facial nerve neuroma may require removal of a segment of the facial nerve as well as a regrafting of the facial nerve with a nerve taken from another site. Common donor sites include a nerve in the neck or a portion of the nerve in the leg.

At surgery, the tumor is completely removed and the two separated segments are reconnected by placing the new segment of nerve graft between these ends. Regrowth of normal nerve endings through the nerve graft will take at least six months to begin, and 12 to 18 months to see the full recuperation of the nerve. In this setting, facial expression is never completely normal, but good results can be obtained.

Cholesterol Granulomas

Cholesterol granulomas are less common and are not really tumors. Rather, they are a mass of gelatinous material which fills the mastoid and middle ear as the result of hemorrhage of blood into the mastoid and middle ear. The material which forms appears bluish-black upon examination of the tympanic membrane. As the material organizes, it can form a firm adhesive material within the mastoid and middle ear which can damage the structures within the middle ear. Surgical ventilation of the middle ear (inserting a tube) is helpful. In aggressive cases, actual surgical excision of all of the cholesterol granuloma is necessary in order to reestablish normal hearing and adequate drainage of the disease process. In most cases, a large bore ventilating tube is inserted into the eardrum and left for prolonged periods of time to prevent recurrence of the cholesterol granuloma.

Malignant Tumors of the Middle Ear and Mastoid (Squamous Cell Cancer of Middle Ear and Mastoid)

Malignant tumors in the middle ear and mastoid are very uncommon. Of these very uncommon tumors, the squamous cell cancers are the most prevalent . These cancers are usually found in individuals who have neglected chronic or long-term drainage and 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.

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.

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 (specialist who studies and diagnoses removed tissue for biopsy) will be able to determine whether cancer is present in the tissues.

CT scan and MRI are necessary in order to help determine the extent of surgery necessary. Squamous cell cancer of the middle ear and mastoid is a fatal disease, if not treated properly. 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.

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: MRI scanning can demonstrate the infiltration of the tumor into soft tissue, specifically tissue in the front of the ear or parotid gland area. MRI¹s 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.

Patient Assessment

Following the physical examination, biopsies and imaging studies, the patient and family should meet with the skull base team — ear surgeon, head and neck surgeon, neurosurgeon, and in some cases plastic surgeon and eye surgeon. Discussions should include the possibility of facial nerve removal and grafting, if the tumor has invaded the facial nerve. In addition, most patients with extensive tumors will lose the hearing and balance functions of the inner ear. In order to isolate the tumor and remove it completely, portions of the ear canal, mastoid and inner ear will be removed in an “enbloc” operation. This means that the structures of the ear canal, drum, middle ear, and inner ear are removed in one piece. This technique reduces the possible spillage of tumor to adjacent sites, but provides a greater chance of cure.

Radiation Therapy

Radiation therapy is generally advised after tumor excision. In the very infirm, radiation therapy may be given in preference to surgery, but it is usually not successful in eradicating the tumor and providing a cure. Radiation therapy is performed after surgery to counter tumor spillage into adjacent tissue. The additional radiation therapy, which begins about four weeks after the operation, is aimed at destroying any cell nests or any tongues of tumor that are in adjacent areas.

Staging of the Tumor

Preoperative staging of the tumor, using imaging studies alone is extremely difficult. The most accurate staging of the tumor in squamous cell cancer of the ear is available after the surgical procedure itself. If the tumor has invaded the dura (covering of the brain), then cure may not be possible, although removal of the tumor and radiation therapy in such cases is performed for palliation to relieve pain and improve survival.