Collaborative Stage

Note 1: According to AJCC, p. 329, "Data from the AJCC Melanoma Staging Database demonstrated a highly significant correlation with increasing mitotic rate and declining survival rates, especially within thin melanoma subgroups."
Note 2: Mitotic rate/count is assessed on primary melanomas, based on the number of mitotic figures in one square millimeter (mm) surrounding either a "hot spot" with the most mitotic figures or a field with a representative mitosis.
Note 3: Record the mitotic rate/count as documented in the pathology report.Use code 999 if there is no documentation or no mention of mitotic rate in the pathology report.

Code	Description
000	0 mitoses per square millimeter (mm) Mitoses absent No mitoses present
001-010	1 - 10 mitoses/square mm (Exact measurement in mitoses/square mm) Examples: 001 1 mitosis per square mm 002 2 mitoses per square mm 010 10 mitoses per square mm
011	11 or more mitoses per square mm
988	Not applicable: Information not collected for this case (If this information is required by your standard setter, use of code 988 may result in an edit error.)
990	Stated as "less than 1 mitosis/square mm" Stated as "nonmitogenic"
991	Stated as "at least 1 mitosis/square mm" Stated as "mitogenic"
998	No histologic examination of primary site.
999	Unknown or no information Not documented in patient record

CS Site-Specific Factor 7
Primary Tumor Mitotic Count/Rate