Clinical | | | | |
Symmetry | Symmetrical | Asymmetrical | Asymmetrical | 5–8, 9 |
Size | Small (<5 mm) | Larger (>5 mm) | Variable | 5–8, 9 |
Border | Regular | Irregular | Irregular | 5–8, 9 |
Colour | Uniform | Variegated | Variegated | 5–8, 9 |
Histological | | | | |
Cytological atypia | Absent | Mild to severe | Severe | 5–8, 9 |
Architectural atypia | Absent | Mild to severe | Severe | 5–8, 9 |
Ultrastructural | | | | |
Melanosomes | Normal | Aberrant | Aberrant | 10, 11 |
Golgi | Normal | Well developed | Well developed | 10, 11 |
Mitochondria | Numerous | Abundant | Abundant | 10, 11 |
Immunohistochemical | | | | |
MMR protein expression | Strong | Intermediate | Decreased | 12 |
p53, HMB45 expression | Absent | Intermediate | Pronounced | 13, 14 |
Proliferation marker expression | Low | Intermediate | High | 15–17 |
Genetic | | | | |
MSI | Absent/Present | Present (+) | Present (+++) | 18, 19 |
Allelic loss | Absent | Present (+) | Present (+++) | 20–22 |
Loss of TSG (p16 and p53) | Absent | Present (+) | Present (+++) | 23 |
Alterations of oncogenes (ras) | Absent | Present (+) | Present (+++) | 24 |