Melanoma - Stage and Survival

Very thin tumors are classified according to Clark's level of invasion, based on the number of layers of skin penetrated by the tumor.

  • Clark's level I.  The melanoma occupies only the epidermis.
  • Clark's level II.  The melanoma penetrates to the layer immediately under the epidermis, the papillary dermis.
  • Clark's level III.  The melanoma fills the papillary dermis and impinges on the reticular dermis, the next layer down.
  • Clark's level IV.  The melanoma penetrates into the reticular or deep dermis.
  • Clark's level V.  The melanoma invades the subcutaneous fat