Clarke's levels

Clarke's levels

schema defining skin lesion malignancy potential, based on the degree of intradermal invasion (Table 1)
Table 1: Clarke's levels, denoting the level of invasion of a skin tumour
LevelFeature
ILesion confined to epidermis (i.e. in situ)
IIEpidermal lesion has just invaded into upper dermis
IIIEpidermal lesion has significantly invaded upper dermis
IVEpidermal lesion has invaded as far as deeper reticular dermis
VEpidermal lesion has invaded through dermis into subcuticular tissues

The greater the depth of lesion penetration, the more liable it is to undergo metastasis.