Clinical Manifestations Melanoma may occur on any skin surface, but the most common site for melanoma in men is on the back, while in women, the most common location is the lower extremity. Clinically, there are numerous types of malignant melanoma. These include superficial spreading melanoma, lentigo maligna melanoma, nodular melanoma, acral lentiginous melanoma, and amelanotic melanoma. Lentigo maligna melanoma occurs in an older patient population, typically on the face. This usually arises within the precursor lesion, lentigo maligna.
Nodular melanomas tend to grow rapidly, over the course of several months.
Nodular melanomas often carry a poor prognosis, because by the time of diagnosis, they have usually invaded deeply into the dermis. Tumor nodules tend to be friable, bleed easily, and may ulcerate. This form of melanoma is the most common form in black patients. These tumors often have a poor prognosis, because by the time of diagnosis, they have often invaded deeply into the dermis. Amelanotic melanoma is a rare form of malignant melanoma, so named because of the lack of pigmentation visible within the tumor.