Cancer of the Head and Neck
Khoa D. Tran
Gady Har-El
Squamous cell carcinoma is the sixth most prevalent cancer and constitutes more than 90% of cancers arising in the upper aerodigestive tract. Approximately 5% of all malignant tumors among men and 2% among women arise in the head and neck. More than 50,000 new cases of head and neck cancer occur each year in the United States, and there are more than 15,000 deaths annually. Worldwide, squamous cell carcinoma of the head and neck affects more than 500,000 people annually. Other tumors that arise in the head and neck region include major and minor salivary gland neoplasms, cervical nodal lymphoma, pharyngeal lymphoma arising from Waldeyer’s ring or other extranodal nonlymphoid sites, and undifferentiated tumors. Thyroid cancer is discussed in Chapter 34. Skin cancer is discussed in Chapter 41.
Approximately 80% to 90% of head and neck cancers may be attributed to exposure to chemical carcinogens such as alcohol and tobacco, which act synergistically. Other common carcinogenic factors include poor dental hygiene, tobacco chewing, betel nut chewing, luetic glossitis (tongue cancer factor), woodworking (nasal and sinus cancer factor), and exposure to nickel compounds (paranasal sinus cancer factor). Radiation exposure may likewise predispose a patient to a variety of carcinomas or sarcomas in the head and neck region depending on the exposure dose and duration. Viral carcinogens have been implicated in some head and neck carcinomas, particularly the Epstein-Barr virus in nasopharyngeal carcinoma.
Head and neck cancers are particularly suitable for definitive anatomic staging according to the tumor-node-metastasis (TNM) system (Table 36-1). Both the primary tumor and the nodes are readily accessible for measurement. The TNM factors have been shown to be both valid prognostic indicators and accurate measures of the extent of disease.
DIAGNOSIS
History and Physical Examination
A careful medical history and physical examination are important in evaluating the head and neck tumors. Examination includes inspection and palpation of all aspects of the head, face, neck, nose, oral cavity, and tongue base. Indirect mirror examination of the nasopharynx and larynx or flexible fiberoptic nasopharyngoscopic examination should be performed. The physician must avoid focusing solely on the area of the tumor and must conduct a complete examination of all areas of the head and neck. Simultaneous or sequential presentation of multiple lesions in the head and neck is not uncommon.
Imaging
Numerous radiographic techniques are available for evaluating the head and neck region. It is essential to correlate radiologic
findings with clinical findings. Plain radiography and barium swallow study are occasionally used with limited information obtained.
findings with clinical findings. Plain radiography and barium swallow study are occasionally used with limited information obtained.
TABLE 36-1. TNM staging classification for most head and neck cancers | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||||||||||||||||
Computed Tomography
Indications for computed tomography (CT) study are listed below.
Evaluating bony involvement and destruction by tumors
Visualizing the extent of tumor invasion
Defining the extent of soft-tissue tumors in sites not easily seen clinically (e.g., the nasopharynx, base of the skull, parapharyngeal space)
Detection of regional metastases
Follow-up on tumor response to radiation therapy and chemotherapy
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) can delineate soft-tissue masses and fascial planes better than CT. MRI characterizes lesions with multiple pulse sequences, provides images in planes other than the axial, and shows vessels without use of contrast material or ionizing radiation. MRI has unique applications in the evaluation of sinus, orbital, and brain tumors since it can differentiate between soft-tissue densities. MRI and CT are not mutually exclusive examinations because each has advantages over the other. CT continues to be used because MRI has a higher cost, longer imaging time, higher motion artifacts, and is contraindicated for patients with implanted metallic foreign bodies (aneurysm clips, neural stimulators, and cochlear implants). Although nuclear scans are not routinely used, positron emission tomography has recently been utilized with promising results in detecting metastatic disease in the neck.
Because 25% of stage III and IV cancers of the head and neck metastasize beyond the cervical lymph nodes, all surgical candidates need chest radiography or chest CT if applicable. CT of the chest can also screen for lung cancer, which accompanies approximately 15% of squamous cell carcinoma of the head and neck. A palpable liver mass, jaundice, and altered liver function tests are indications for abdominal CT. Bone pain or neurologic signs are indications for radiologic evaluation for possible bone and brain metastases.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
