[1] It tends to grow more rapidly in thickness (vertically penetrate the skin) than in diameter compared to other melanoma subtypes.

[2] Instead of arising from a pre-existing mole, it may appear in a spot where a lesion did not previously exist.

Since NM tends to grow in depth more quickly than it does in width, and can occur in a place that did not have a previous lesion, the prognosis is often worse because it takes longer for a person to be aware of the changes.

[3]: 696 The microscopic hallmarks are: Therapies for metastatic melanoma include the biologic immunotherapy agents ipilimumab, pembrolizumab, and nivolumab; BRAF inhibitors, such as vemurafenib and dabrafenib; and a MEK inhibitor trametinib.

[4] Important prognosis factors for nodular melanoma include: