Melanoma/Amelanotic Melanoma is a malignant tumor of the melanocytes, cells that are derived from the neural crest, and although most melanomas arise in the skin, some may also arise from mucosal surfaces or other sites to which neural crest cells migrate (General pg). More than half of the cases arise in apparently normal areas of the skin and occur predominantly in adults (General pg). In women it occurs more commonly on the extremities and in men on the trunk or head and neck, however, it can arise from any site on the skin surface (General pg).

Melanoma is usually classified into stages and is depending on how deep the cancer cells have invaded the body (Melanoma pg). Stage 1 involves a growth on the skin, such as a mole (Melanoma pg). In Stage 2, the tumor is has penetrated deeper, however it has not spread to other parts of the body (Melanoma pg). In Stage 3, the cancer has spread to a lymph basin or other tissue and in Stage 4, it has spread to distant body areas (Melanoma pg).

Amelanotic melanoma is an unpigmented malginant consisting of cells from melanoblasts however, not forming melanin and may be found in any of the four stages (Melanoma pg).

Early signs in a nevus include darker or variable discoloration, itching, an increase in size, or the development of satellites, while later signs include ulceration or bleeding (General pg). A biopsy, preferably by local excision, is recommended for any suspicious lesions and the specimens examined by a pathologist to allow...

Lesions which appear suspicious should never be shaved off or cauterized (General pg). It is difficult, even for experienced dermatopathologists, to distinguish between benign pigmented lesions and early melanomas, therefore, a second review by a qualified independent pathologist should be considered (General pg). Prognosis is affected by clinical and histological factors, as well as by anatomic location of the lesion (General pg). Prognosis is also affected by the thickness, level of invasion, mitotic index, presence of tumor infiltrating lymphocytes, the number of regional lymph nodes involved, and ulceration or bleeding (General pg). Microscopic satellites in stage 1 melanoma may be a poor prognostic histologic factor, however, this is controversial (General pg). Young females with melanomas on the extremities generally have a better prognosis (General pg). Whether the tumor has spread to regional lymph nodes or distant sites is the basis for clinical staging (General pg). "For disease clinically confined to the primary site, the greater the thickness and depth of local invasion of the melanoma, the higher the chance of lymph node or systemic metastases and the worse the prognosis" (General pg).
This disease can spread by local extension or by hematogenous routes to distant sites, such as the lungs and liver (General pg). The risk of relapse decreases over time, however, late relapses are not uncommon (General pg).

Clinicopathologic cellular subtypes of…