schemas for melanoma. However, with further study, it has been shown that Clark's level has a lower predictive value, is less reproducible, and is more operator-dependent as compared with Breslow's depth. Thus, in the current (2010) AJCC staging system, Clark's level has prognostic significance only in patients with very thin (Breslow depth <1 mm) melanomas. Five anatomical levels are recognized, and higher levels have worsening prognostic implications. These levels are: Level 1: Melanoma confined to the epidermis (melanoma in situ) Level 2: Invasion into the papillary dermis Level 3: Invasion to the junction of the papillary and reticular dermis Level 4: Invasion into the reticular dermis Level 5: Invasion into the subcutaneous fat See also ABCD guideline American Joint Committee on Cancer (AJCC) Cancer staging References External links Melanoma Staging Systems. National Cancer Institute. A resource on Clark's levels and Breslow's depth. Cancer staging Dermatologic terminology Histopathology Melanocytic nevi and neoplasms