ABSTRACT
Background Malignant melanoma (MM) is the most common fatal skin cancer. It usually stems from dermic or epidermic neuralcrest derived melanocytes. However, melanocytes located in other regions of the body such as the meninges, the choroidal tissue of the eye, the digestive tract, the mucosal surfaces, and the lymph nodes can also give rise to MM.1
Currently, there are no proven causes of MM, but the most likely associated factor is episodic exposure to the ultraviolet (UV) component of sun rays.2 The risk of melanoma is relatively higher in fair-skinned individuals, particularly those with blond or red hair who sunburn and freckle easily in contrast to those with darker complexions. The sites of predilection for MM are primarily related to the areas of intermittent exposure to the sun, such as the back in men and the lower leg in women, with relative sparing to the more frequently exposed sites such as the face, hand, and forearms.2 Despite the continuous advances in prevention, early detection, and treatment, the worldwide incidence and mortality rate of MM are increasing dramatically. The National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database documents increases of 619% in annual diagnosis of cutaneous melanoma and of 165% in annual mortality from 1950 to 2000.3 Malignant melanoma has four histogenetic types: superficial spreading, lentigo maligna, nodular, and acral lentiginous melanoma. Clinical signs that may be indicative of possible MM are asymmetry, border irregularity, color variegation, increase in diameter, elevation, ulceration, and bleeding of pigmented lesions.1
