History:

Microstaging is an integral part of the staging and clinical management of melanoma. Two methods have been used. The Breslow microstaging method measures the thickness of the lesion in millimeters using an ocular micrometer. The total vertical height of the melanoma is measured from the granular layer to the area of deepest penetration. The Clark method assesses the level of penetration into the various skin layers.

Clark Classification System of Microstaging

Level I: Confined to the epidermis (in situ) Level II: Invasion into the papillary dermis Level III: Penetration to the papillary-reticular interface Level IV: Invasion into the reticular dermis Level V: Penetration into subcutaneous fat