Collaborative Stage Data Set - Revised 10/21/2010 FINAL

NETStomach

CS Site-Specific Factor 6
Mitotic Count

Note 1: The mitotic count, the number of mitoses per 10 high-power fields (HPF), is an element in a proposed grading scheme for neuroendocrine tumors (NET) of the gastrointestinal system. This site-specific factor presumes the denominator of 10 HPF, so just the numerator (the mitotic count) is coded here. For other schemas in which mitotic count is collected, the denominator may vary.
Note 2: As described in the AJCC chapter on NETs, 10 HPF at a magnficiation objective of 40 (40x) are equivalent to 2 square millimeters (mm).
Note 3: Record mitotic count to the nearest tenth as documented in the pathology report. For example, a mitotic count of 3/10 HPF would be coded 030.
Note 4: Code the specific mitotic count only per 10 HPF or 2 square mm; assume the denominator is 10 HPF or 2 square mm if not specified. Use code 996 only if the mitotic count is expressed with a specific denominator other than 10 HPF or 2 square mm.

Code	Description
000	0.0 mitoses per 10 high-power fields (HPF) (40x field) 0.0 mitoses per 2 square millimeters (mm) Mitoses absent No mitoses present
001-008	0.1 - 0.8 mitosis per 10 HPF (40x field) 0.1 - 0.8 mitosis per 2 square mm
009	0.9 mitosis per 10 HPF (40x field) 0.9 mitosis per 2 square mm Stated as less than 1 mitosis per 10 HPF (40x field) Stated as less than 1 mitosis per 2 square mm
010-500	1 - 50 mitoses per 10 HPF (40x field) 1 - 50 mitoses per 2 square mm
510	51 or more mitoses per 10 HPF (40x field) 51 or more mitoses per 2 square mm
888	OBSOLETE DATA CONVERTED V0200 See code 988 Not applicable for this site
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.)
990	Specific number not stated, described as less than 2 mitoses per 10 HPF (40x field) Specific number not stated, described as less than 2 mitoses per 2 square mm Stated as low mitotic count or rate with no specific number
991	Specific number not stated, described as between 2 and 20 mitoses per 10 HPF (40x field) Specific number not stated, described as between 2 and 20 mitoses per 2 square mm
992	Specific number not stated, described as more than 20 mitoses per 10 HPF (40x field) Specific number not stated, described as more than 20 mitoses per 2 square mm Stated as high mitotic count or rate with no specific number
995	OBSOLETE DATA CONVERTED V0203 See code 991 Specific number not stated, described as between 2-20 mitoses per 10 high-power fields (40x field) Specific number not stated, described as between 2-20 mitoses per square millimeter
996	Mitotic count described with denominator other than 10 HPF (40x field) or 2 square mm
997	OBSOLETE DATA CONVERTED V0203 See code 992 Specific number not stated, described as more than 20 mitoses per 10 high-power fields (40x field) Specific number not stated, described as more than 20 mitoses per square millimeter
998	No histologic examination of primary site
999	Unknown or no information Not documented in patient record

List of Schemas NETStomach Schema Index

NETStomach

CS Site-Specific Factor 6Mitotic Count

CS Site-Specific Factor 6
Mitotic Count