Melanoma

Melanoma accounts for about 3% of all cancers in the United States and for approximately 1% of all cancer deaths. The incidence of melanoma is increasing by 4% to 8% per year--the fastest growing incidence of any type of cancer.¹ In the United States, the lifetime risk of invasive melanoma is 1 in 65, a 2000% increase since 1930.² The risk increases to 1 in 37 if noninvasive melanoma in situ is included.²

Melanoma may arise anywhere on the body, but most commonly affects sun-exposed areas. The face in men and legs in women are common sites of involvement. New or changing lesions--particularly pigmented lesions--warrant a biopsy. Most experts agree that biopsy is indicated for any lesion that could be a melanoma because the consequences of metastatic melanoma may be catastrophic. Dermoscopy is another tool used by specialists for assessing pigmented lesions.

Risk factors include sun exposure, fair skin, genetic defects, advanced age, and the presence of many nevi. Although most melanomas appear de novo, some arise from nevi (usually congenital, not dysplastic, nevi).

Clinical variants include superficial spreading melanoma (A), nodular melanoma, lentigo maligna melanoma, acral lentiginous melanoma, and amelanotic melanoma (B). If melanoma is confined to the epidermis or is less than 0.76 mm thick at the time of diagnosis, the cure rate is about 99%. Metastatic melanoma has a poor prognosis.

Melanoma is treated with surgical excision. Controversy exists about the use of sentinel node biopsy to assess for the presence of metastases when melanomas are more than 1 mm deep.³

References:

REFERENCES:

1.

Cummins DL, Cummins JM, Pantle H, et al. Cutaneous malignant melanoma. Mayo Clin Proc. 2006;81:500-507.

2.

Swetter SM. Malignant melanoma. Available at:

http://www.emedicine.com/DERM/topic257.htm

.Accessed June 11, 2006.

3.

Ra JH, McMasters KM, Spitz FR. Should all melanoma patients undergo sentinel lymph node biopsy?Curr Opin Oncol. 2006;18:185-188.