Melanoma Amelanotic

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 for microstaging (General pg). 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 malignant melanoma are: "Superficial spreading, Nodular, Lentigo maligna, Acral lentiginous (palmar/plantar and subungual), Miscellaneous unusual types: Mucosal lentiginous (oral and genital), Desmoplastic, Verrucous" (General pg). Studies have been found to be considerably variable concerning the histologic diagnosis of melanomas and benign pigmentented lesions (General pg). One study, examined by a panel of experienced dermatopathologists, found there was discordance on the diagnosis of melanoma vs. benign lesions in 37 of 140 cases (General pg).

Another study, examined by a panel of expert pathologists, revealed that 38% of cases had two or more discordant interpretations (General pg). Such studies prove how difficult it is to distinguish between benign pigmented lesions and early melanoma (General pg). Surgery is the most common treatment for melanoma, in fact some 95% of cases are treated with surgery first, then other treatments such as, chemotherapy, immunotherapy, radiation therapy, or a combination of the three, may be added as needed (Melanoma pg).

An example of combination therapy would be three days of DTIC and cisplatin followed by eight days of Interleukin-2 and Interferon per month (Melanoma pg). Chemotherapy can be systemic treatment, affecting cancerous cells over the entire body, or localized, called infusion and perfusion, where chemicals are placed into the melanoma area (Melanoma pg). Although, Interferon and Interleukin are common forms of Immunotherapy, vaccine therapy is another form, however, most all vaccine therapies are considered experimental and unproven, yet many look promising (Melanoma pg).

Exfoliative Cytopathology includes gynecologic specimens, such as pap smears, non-gynecological specimens and outside slides (Section pg). Prepared specimens are sent to cytotechnologists for preliminary screening and evaluated by a cytopathogist (Section pg). Fine Needle Aspiration, FNA, biopsies are performed by cytopathologists who smear, stain.