Melanoma: etiology, treatment, and dental implications

Melanoma is one of the most serious skin cancers. It arises from neural crest-derived melanocytes located in the epidermis or dermis of the skin. Melanoma also can arise from melanocytes located in other regions of the body such as the eye, meninges, digestive tract, mucosal surfaces, or lymph nodes. There are no proven causes of melanoma but the most commonly associated factor is episodic exposure to the sun. Melanoma is a common cancer that has been increasing in incidence for the last 35 years. The median age at the time of diagnosis is 53 years. It is much more common in whites than in people of color. Five-year survival rates for melanoma of the skin have been increasing since 1976. There are four types of melanoma: superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, and acral lintiginous melanoma. Clinical signs indicating possible melanoma are asymmetry, border irregularity, color variation, increase in diameter, elevation, ulceration, and bleeding of pigmented lesions. Histopathologic findings (tumor thickness, tumor invasion), surface ulceration, spread to lymph nodes, and distant metastases are used to project patient prognosis. Treatment consists of surgical excision, lymph node dissection, limb perfusion, regional chemotherapy infusion, radiation, intralesional immunotherapy, systemic chemotherapy, and/or interferon-alpha, depending on the staging of the melanoma. Oral melanomas are rare; however, approximately 20% of all melanomas are found in the head and neck region. The role of the dentist is to be alert for changes in pigmented lesions of the oral mucosa and skin of the head and neck. Lesions suspected of melanoma must be biopsied, which usually involves referral of the patient.