American Board of Surgery Qualifying Exam (ABS QE) Practice Test

Which type of melanoma is considered the most aggressive?

1. Superficial spreading melanoma

2. Lentigo melanoma

3. Nodular melanoma

4. Acrolentiginous melanoma

The correct answer is: Nodular melanoma

Nodular melanoma is recognized as the most aggressive type of melanoma due to its specific growth characteristics and typical presentation. This form of melanoma often arises suddenly as a raised, blue-black lesion and tends to grow vertically rather than horizontally. Due to its rapid invasive potential, nodular melanoma can metastasize more quickly to lymph nodes and distant sites, which significantly increases the risk of advanced disease and adverse outcomes. The vertical growth phase of nodular melanoma allows it to penetrate deeper into the skin layers and into the surrounding tissues earlier than other types, resulting in a higher thickness (Breslow thickness) at diagnosis. This characteristic is a key factor influencing prognosis. Early detection is critical for this melanoma type, as the chances of cure diminish considerably once it has invaded deeper tissues or lymphatic systems. In contrast, other types of melanoma, such as superficial spreading melanoma, typically exhibit a radial growth phase, which may allow for greater opportunities for early detection and intervention. Lentigo melanoma also usually presents more gradually and is often seen in older individuals, which can influence the timing of diagnosis. Acrolentiginous melanoma, while it can also be aggressive, tends to be less prevalent and generally has different considerations in terms of demographics and location of lesions.