How is morphology of melanoma?

➢ Unlike benign nevi, melanomas often exhibit striking variations in pigmentation, including shades of black, brown, red, dark blue, and gray ➢ The borders are irregular and often “notched.” ➢ Microscopically, malignant cells grow as poorly formed nests or as individual cells at all levels of the epidermis (pagetoid spread) and in expansile dermal nodules; ➢ These constitute the radial and vertical growth phases, respectively ➢ Of note, superficial spreading melanomas are often associated with a brisk lymphocytic infiltrate a feature that may reflect a host response to tumor-specific antigens.