Collaborative Stage Data Set - Revised 05/31/2011 FINAL
| Code | Description |
| 010 | Clark level I In situ, intraepidermal, intraepithelial, noninvasive Basement membrane of epidermis is intact |
| 020 | Clark level II Papillary dermis invaded |
| 030 | Clark level III Papillary-reticular dermal interface invaded |
| 040 | Clark level IV Reticular dermis invaded |
| 050 | Clark level V Subcutaneous tissue invaded (through entire dermis) |
| 888 | OBSOLETE DATA CONVERTED V0200 See code 988 Not applicable for this site |
| 987 | Not applicable, not squamous cell carcinoma of skin of eyelid |
| 988 | Not applicable: Information not collected for this case (May include cases converted from code 888 used in CSv1 for "Not applicable" or when the item was not collected. If this item is required to derive T, N, M, or any stage, use of code 988 may result in an error.) |
| 998 | No histologic examination of primary site |
| 999 | Unknown or no information Not documented in patient record |