What type of melanoma has the worst prognosis due to early invasion?

• A. Superficial spreading melanoma
• B. Lentigo maligna melanoma
• C. Nodular melanoma
• D. Acral lentiginous melanoma

Answer: (C)

Nodular melanoma is characterized by its rapid vertical growth phase, which leads to early invasion into deeper layers of the skin. This aggressive behavior contributes to its worse prognosis compared to other types of melanoma. The specific growth pattern of nodular melanoma allows it to metastasize sooner, often presenting at a more advanced stage when diagnosed. In contrast, other types, such as superficial spreading melanoma and lentigo maligna melanoma, typically have a horizontal growth phase before they start deep tissue involvement, allowing for a better prognosis if caught early. Acral lentiginous melanoma, while also a serious type, often presents in non-sun-exposed areas and may demonstrate different patterns of invasion but does not generally match the rapid invasion seen in nodular melanoma. Thus, the nature of nodular melanoma, with its early invasion and tendency for poorer outcomes, solidifies its position as the type with the worst prognosis among these options.