Nodular melanoma (NM) is the most aggressive form of melanoma. It grows in vertical direction from the outset and grows very fast (months). Nodular melanoma has no known precursor. It is a small black, or if amelanotic, pink nodule that simply enlarges. The lesions tend to bleed.
The microscopic hallmarks are:
Dome-shaped at low power
Epidermis thin or normal
Dermal nodule of melanocytes with a 'pushing' growth pattern
