Chances of cure are maximal when lymphocytic infiltration is limited to the most superficial lesions and decrease with deeper levels of tumor cell invasion. Metastasis of melanoma occurs via lymphatics and blood vessels. Local metastasis results in formation of nearby satellite papules or nodules that may or may not be pigmented. Direct metastasis to skin or internal organs may occur, and occasionally metastatic nodules or enlarged lymph nodes are discovered before the primary lesion is identified. Melanomas arising from mucous membranes have a poor prognosis, although they often seem quite limited when discovered.
Treatment is by surgical excision.
Thicker lesions may deserve more radical surgery and sentinel node biopsy. Lentigo maligna melanoma and lentigo maligna are usually treated with wide local excision and, if necessary, skin grafting. Intensive x-ray therapy is much less effective than surgery. Spreading or nodular melanomas are usually treated by wide local excision extending down to the fascia. Therapeutic lymph node dissection may be recommended when there is node involvement.