(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
- No "radial growth phase"