Squammous cell carcinoma of Temporal bone: A current review

Squamous cell carcinoma is the most common malignancy of the external auditory canal, middle ear, and mastoid. Surgical resection is the cornerstone of treatment, with T1 lesions of the external auditory canal treated by lateral temporal bone resection and more advanced lesions treated by subtotal or total temporal bone resection.

Clinical features

Patients with cancer of the temporal bone most often present when aged 60 years or older, although any age group, including children, can be affected.

Symptoms and signs of temporal bone lesions are summarized as follows:

· Otalgia (80-85%)

· Otorrhea (40-75%)

· Facial paralysis (25%)

· Hearing loss (45-80%)

· Tinnitus (8-10%)

· Vertigo

· Auricular lesion

· External canal mass (10%)

· Parotid mass (19%)

· Skin lesions

· CN V, IX, I, XI deficits (30%)

Workup in malignant tumors of the temporal bone

Routine preoperative testing includes complete blood counts (CBCs), electrolyte level tests, renal function tests, liver function tests, coagulation.

Imaging studies can include the following:

· HRCT and MRI scan- Imaging is important in TBMs for accurate tumor and node staging as many patients have limited findings on physical examination. Highresolution computed tomography of the temporal bone offers the most accurate method for the evaluation of bone erosion due to malignancies. However, a reported limitation of CT is its inability to distinguish between tumor and fluid in the middle ear, soft tissue or mucosal thickening in the absence of bone erosion. Also, spread along fascial planes and neurovascular structures can be difficult to detect. MRI can provide excellent differentiation between soft-tissue tumor margin, muscle and soft-tissue infiltration, and can help in distinguishing tumor from obstructive inflammatory changes. In addition, obstruction of the sigmoid sinus and encasement of the petrous internal carotid artery are better detected on MRI than CT, because of the vascular signal void seen on precontrast MRI and the flow enhancement of the sigmoid sinus seen on postcontrast MRI. Tumor extension, specially cranial spread into the middle and posterior cranial fossa and caudal spread into the infratemporal fossa, is also better detected on MRI. Enhanced T1-weighted spin-echo images with fat-signal suppression are most suitable for this purpose. MRI has also made it possible to confidently diagnose perineural spread of malignancies. Fat saturation gadolinium-enhanced magnetic resonance (MR) scans are often capable of detecting subtle tumor tracking along the fifth and seventh cranial nerves, as well as other nerves that travel through the many foramina of the skull base, before the lesions have grown sufficiently large to affect the surrounding bone.

· Chest radiography - If the histology indicates squamous cell carcinoma, obtain plain radiographs or CT scans of the chest to rule out metastasis

· CT scanning of the chest, abdomen, or pelvis - This is not necessary unless the biopsy specimen of the temporal bone tumor reveals a tumor with a known propens