Resection of the Temporal Bone

Squamous cell carcinoma of the EAC has a reported incidence of approximately 1 per 1 million per year. Other pathologies may involve the temporal bone, including basal cell carcinoma, adenocarcinoma, and adenocystic carcinoma.

Primary malignancies of the temporal bone may also arise in the EAC, middle ear, mastoid and, rarely, in the jugular foramen and petrous apex.

Secondary tumors may involve the temporal bone as a result of spread from adjacent structures, such as the concha, pinna, parotid gland, and dura.

Metastasis to the temporal bone from distant sites can also occur, often at the petrous apex.

Carcinoma of the ear canal may be difficult to distinguish from chronic otitis externa, malignant otitis externa, cholesteatoma of the ear canal, temporal bone osteonecrosis, and otitis media.

Symptoms include:

• Persistent, deep-seated, unrelenting pain

• Bloody otorrhea

• Hearing loss

• Weakness of the facial nerve

• Deficits of other cranial nerves

• Diffuse edema or stenosis of the ear canal

Maintain a high index of suspicion for any condition of the EAC that does not respond to topical or systemic antibiotic treatment.

Cancer of the temporal bone may occur in younger people who are more likely to have aggressive disease.

Findings include a friable, necrotic, bloody broad-based mass, polyp or ulceration, or diffuse thickening or stenosis of the EAC.

Define the involvement of cartilaginous and bony canal with microscope examination of the ear.

Evaluate the function of the facial nerve and other cranial nerves.

Determine whether the cancer appears to involve the tympanic annulus or the tympanic membrane, middle ear (middle ear mass or effusion), neck (masses or tenderness), and temporomandibular joint (TMJ) (trismus).

Perform an audiogram.

Determine the extent of disease for staging using examination and imaging.

Usually, both magnetic resonance imaging (MRI) and computed tomography (CT) will be required to adequately stage the disease process.

• High-resolution thin cut CT of the temporal bone

• MRI of the skull base with and without contrast

• CT or MRI of the neck with contrast

Encroachment of cancer in the region of the internal carotid artery (ICA) should be investigated with CT angiography or angiography with the balloon occlusion test if resection of the ICA is considered. Venography is helpful for evaluation of the dural sinuses.

Screen for additional pathology with chest radiography and liver function testing.

In malignant tumors with a high predilection for systemic spread, such as melanoma, CT scanning of the chest, abdomen, and pelvis, as well as whole-body bone scanning, should be performed.

Positron emission tomography (PET) may be considered for the evaluation of local involvement and distant metastasis.

While a survey of the extent of disease with combined imaging modalities is generally predictive of intraoperative findings, the extent of the cancer may be underestimated, especially with respect to spread posteriorly, superiorly, and medially.

Primary cancer of the EAC can be staged according the modified Pittsburgh system as T1 through T4, depending on the degree of bone, cartilage, and soft tissue involvement ( Table 141.1 ).

Sleeve resection of skin of EAC for very limited lesions of the external auditory meatus and lateral EAC

Lateral temporal bone resection for lesions limited to the EAC (T1, T2)

Subtotal temporal bone resection for cancer invading the middle ear and mastoid (T3, T4)

Total temporal bone resection for cancer extending to the petrous apex

Cancer extending to the TMJ, neck, dura, or infratemporal fossa (ITF) will require resection including these regions

Extension into the cavernous sinus and brain parenchyma makes total extirpation of the cancer nearly impossible, and the possibility of cure becomes unlikely, even with the addition of aggressive adjuvant radiation therapy and chemotherapy.

Involvement of the internal carotid canal is also problematic, but it is not an absolute contraindication to surgical resection.

Compromised medical status precluding a prolonged general anesthetic and recovery.

Biopsy is performed by direct incision; a staging mastoidectomy is not appropriate because it reduces the reliability of staging radiography and it may compromise the surgical margins of resection.

A team approach is often necessary for advanced cancer, including the cooperation of a Neurotologist, Head and Neck Surgeon, Reconstructive Surgeon, Neurosurgeon, Pathologist, Radiation Oncologist, and Intensivist, as well as experienced nursing teams.

Consider whether a simultaneous osseointegrated implant for hearing device or prosthetic ear is indicated, or discuss with the patient that these options may be considered after primary surgical management of the cancer has been completed.

The patient’s medical status should be optimized before surgery. Significant conditions, such as coronary artery disease, chronic obstructive pulmonary disease, diabetes mellitus, bleeding disorders, and malnutrition should be identified and treated preoperatively.