A. Squamous cell carcinoma (SCC)
Squamous cell carcinoma (SCC) arising from the aerodigestive tract is the most common neoplasm of the head and neck. SCC is strongly associated with tobacco and alcohol use. Despite advances in tumor resection, reconstruction techniques (which allow for larger surgical margins), and adjuvant treatments, the 5-year rate of disease-free survival is still approximately 50% (N Engl J Med 2004;350:1937). This is thought to be due to the extensive lymphatic system of the head and neck (which increases the incidence of metastasis), anatomic constraints on achieving adequate surgical margins, the invasive nature of SCC, the multiplicity of primary tumors, and the concurrence of other alcohol- and tobacco-related illnesses present in this patient population.
- Workup of malignancies includes a thorough head and neck physical examination and history, CT or MRI scan, positron emission tomography (PET) scan, and intraoperative endoscopic biopsies (to assess extent of the tumor, metastasis, presence of multiple primaries, and to obtain tissue for pathologic analysis). Treatment of SCC involves a multidisciplinary team consisting of head and neck surgeons, radiation oncologists, medical oncologists, pathologists, and speech/swallowing therapists.
- Treatment of SCC is complex and based on location, nodal involvement, local invasion, and metastasis. Most tumors are treated by surgical resection and neck dissection, followed by postoperative radiotherapy. Recent studies suggest that surgical resection followed by concurrent radiotherapy and chemotherapy improve local/regional control and disease-free survival (N Engl J Med 2004;350:1937, N Engl J Med 2004;350:1945). However, this intense combined treatment results in significant adverse effects. Due to the complex anatomy and physiology of the head and neck and the variable presentation of SCC, surgical approach and resection must be individualized on a case-by-case basis.
- Molecular targeting of epidermal growth factor-receptor and tyrosine kinase has shown promising results with less toxicity than chemotherapy and may prove to be a mainstay treatment of SCC (Br J Cancer 2007;96:408).
- Anatomic distribution of SCC
1.Laryngeal SCC often presents with sore throat (supraglottic), hoarseness, stridor, dysphagia, and persistent cough. Small lesions are successfully treated with local laser resection or radiotherapy alone. Moderate-sized lesions are also managed with laser resection; however, increasing evidence has shown these cancers to be highly responsive to primary concurrent chemoradiotherapy (N Engl J Med 2003;349:2091). Advanced SCC of the larynx requires partial or total laryngectomy with creation of a tracheoesophageal speech fistula.
2.Nasopharyngeal SCC is most common in Asia and Africa, where it is associated with the Epstein-Barr virus. Current treatment consists of combined chemoradiotherapy, with surgical resection reserved for residual disease (Lancet 2005;365:2041). Metastasis is very common.
3.Oral cavity SCC usually presents as nonhealing ulcers. Treatment is primarily surgical followed by postoperative radiotherapy. At times, the mandible is involved, necessitating mandibulectomy followed by reconstruction.
4.Tongue base SCC is often detected at advanced stages and is among the most difficult malignancies to treat. Emerging transoral laser resection has decreased the complications of surgical resection, but aspiration remains a significant concern following treatment.
5.A neck mass in an adult must be considered malignant until proven otherwise. These neck masses are generally metastatic SCC from the upper aerodigestive tract, especially the base of the tongue and tonsil. Primary tumors arising in the neck are less common but include lymphoma, soft-tissue sarcomas, thyroid carcinoma, salivary gland carcinoma, and neuroendocrine malignancies.
- Other malignancies of the head and neck
1.Mucoepidermoid carcinoma, adenoid cystic carcinoma, and adenocarcinoma can arise from the major or minor salivary glands or aerodigestive tract. Treatment includes resection followed by radiotherapy. Injury to the facial nerve (CN VII) is the most common complication of surgery when the parotid gland is involved. Five-year survival is approximately 50%.
2.Melanoma of the head and neck can be cutaneous, mucosal, or metastatic from an unknown primary. Head and neck melanoma represents 25% of all cutaneous melanomas. Melanoma is treated by complete surgical resection with wide excision. Melanoma is highly metastatic and notoriously chemo- and radioresistant, with 5-year survival rates of 6% to 30% for advanced disease (J Clin Oncol 2001;19:3635).
B. Benign neoplasms of the head and neck
- Nasopharyngeal neoplasms
1.Papillomas are benign, wartlike growths on the septum or lateral nasal wall and are associated with a 10% incidence of squamous cell carcinoma. Wide local excision is necessary to prevent recurrence.
2.Juvenile nasopharyngeal angiofibromas occur in adolescent boys and usually present with nasal obstruction and recurrent epistaxis. Treatment is complete surgical excision. Angiography and embolization of the vascular supply 24 hours prior to resection helps to minimize blood loss.
- Oral cavity benign lesions include papillomas, hemangiomas, lymphatic malformations, mucous cysts, and granular cell tumors. Premalignant changes include leukoplakia (white hyperkeratotic patches) and erythroplakia (velvet red patches).
1.Ameloblastoma is a locally invasive tumor that occurs most frequently in the mandible. It often requires partial resection and reconstruction of the mandible.
1.Paragangliomas arise from the paraganglionic cells of the autonomic nervous system. These are classified as jugulotympanic, vagal, sinonasal, laryngeal, and carotid body tumors. Approximately 3% of paragangliomas produce catecholamines. Angiography allows for embolization prior to surgical excision (within 24 to 48 hours).
2.Schwannomas are tumors derived from the Schwann cells of peripheral nerves and have a predilection for the head and neck. Treatment is excisional.
3.Neurofibromas also arise from peripheral nerves and are usually associated with neurofibromatosis type I. These may form massive plexiform accumulations in the neck. Treatment is excisional.
- Salivary gland. Pleomorphic adenoma is the most common of all salivary gland tumors, followed by Warthin tumor (cystadenoma lymphomatosum). Pleomorphic adenomas grow slowly over many years, are painless, and commonly occur in the parotid gland. Facial nerve palsy is rare. Diagnosis can be made with fine-needle aspiration, and treatment consists of surgical resection.
- Acoustic neuromas (ANs) are benign schwannomas of CN VIII that arise at the skull base. ANs can be nonhereditary or associated with neurofibromatosis type 2. Early signs of AN are hearing loss, vertigo, or facial paralysis due to compression of cranial nerves. AN requires surgical resection.