CS Extension

Notes

**Note 1**: If there is a discrepancy between the Clark level and the pathologic description of extent (invasion into the layers of the dermis), use the higher (more extensive) code. **Note 2**: Code the greatest extent of invasion from any procedure performed on the lesion, whether it is described as a biopsy or an excision. For example, if a punch biopsy with involvement of Clark level IV is followed by a re-excision with residual tumor involving Clark level II, use code 300 (Clark level IV). **Note 3**: Satellite lesions/nodules or in-transit metastases are coded in CS Lymph Nodes. **Note 4**: Ulceration of the melanoma is coded in CS Site-Specific Factor 2.
Code Description AJCC 7 T AJCC 6 T Summary Stage 1977 T Summary Stage 2000 T
000 In situ, intraepidermal, intraepithelial, noninvasive
(Basement membrane of the epidermis is intact)
Clark level I		 Tis Tis IS IS
100 Papillary dermis invaded
Clark level II		 Thickness Ulceration AJCC7 Thickness Ulceration AJCC6 L L
200 Papillary-reticular dermal interface invaded
Clark level III		 Thickness Ulceration AJCC7 Thickness Ulceration AJCC6 L L
300 Reticular dermis invaded
Clark level IV		 Thickness Ulceration AJCC7 Thickness Ulceration AJCC6 L L
310 Stated as T1a with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
315 Stated as T1b with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
320 Stated as T1 [NOS] with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
330 Stated as T2a with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
335 Stated as T2b with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
340 Stated as T2 [NOS] with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
350 Stated as T3a with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
355 Stated as T3b with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
360 Stated as T3 [NOS] with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
370 Stated as T4a with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
375 Stated as T4b with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
380 Stated as T4 [NOS] with no other information on extension Extension Thickness Ulceration T Category AJCC7 Extension Thickness Ulceration T Category AJCC6 L L
400 Skin/dermis, NOS
Localized, NOS		 Thickness Ulceration AJCC7 Thickness Ulceration AJCC6 L L
500 Subcutaneous tissue invaded (through entire dermis)
Clark's level V		 Thickness Ulceration AJCC7 Thickness Ulceration AJCC6 L RE
800 Further contiguous extension:
Underlying cartilage, bone, skeletal muscle		 Thickness Ulceration AJCC7 Thickness Ulceration AJCC6 D D
950 No evidence of primary tumor T0 T0 U U
999 Unknown; extension not stated
Primary tumor cannot be assessed
Not documented in patient record		 Thickness Ulceration AJCC7 Thickness Ulceration AJCC6 U U
- For CS Extension codes 100-300, 400-800, and 999 ONLY, the T category for AJCC 7staging is assigned based on the values of CS Site-Specific Factor 1, Measured Thickness, CS Site-Specific Factor 2, Ulceration, and for certain cases CS Site-Specific Factor 7, Primary Tumor Mitotic Count/Rate, as shown in the Thickness, Ulceration AJCC 7 Table. - For CS Extension codes 310-380 ONLY, the T category for AJCC 7 staging is assigned based on the values of CS Extension, CS Site-Specific Factor 1, Measured Thickness, CS Site-Specific Factor 2, Ulceration, and for certain cases CS Site-Specific Factor 7, Primary Tumor Mitotic Count/Rate, as shown in the ExtensionThickness Ulceration T Category AJCC 7 table. - For CS Extension codes 100-300, 400-800, and 999 ONLY, the T category for AJCC 6 staging is assigned based on the values of CS Site-Specific Factor 1, Measured Thickness, and CS Site-Specific Factor 2, Ulceration, as shown in the Thickness Ulceration AJCC 6 Table. - For CS Extension codes 310-380 ONLY, the T category for AJCC 6 staging is assigned based on the values of CS Extension, CS Site-Specific Factor 1, Measured Thickness, and CS Site-Specific Factor 2, Ulceration, as shown in the Extension, Thickness, Ulceration, T Category AJCC 6 Table.