Collaborative Stage

Note 1: Isolated tumor cells (ITCs) are defined as single tumor cells or small clusters not greater than 0.2 millimeter (mm), usually detected by immunohistochemistry (IHC), hematoxylin and eosin stains (H and E) (see CS Lymph Nodes code 050), or molecular (MOL) methods (Reverse Transcription Polymerase Chain Reaction, RT-PCR) (see CS Site-Specific Factor 5). ITCs do not usually show evidence of malignant activity (e.g., proliferation or stromal reaction.)
Note 2: When CS Lymph Nodes is coded 000, use codes 000-009 only to report results of IHC. Otherwise code 987 in this field.
Note 3: If it is unstated whether or not tests are done for IHC, assume they are not done.
Note 4: If the record states N0(i+) and no other information, code to 009.

Code	Description
000	Regional lymph nodes negative on routine hematoxylin and eosin (H and E), no immunohistochemistry (IHC) OR unknown if tested for isolated tumor cells (ITCs) by IHC studies Nodes clinically negative, not examined pathologically
001	Regional lymph nodes negative on routine H and E, IHC studies done, negative for tumor
002	Regional lymph nodes negative on routine H and E, IHC studies done, positive for ITCs (Tumor cell clusters not greater than 0.2 millimeter (mm))
009	Regional lymph nodes negative on routine H and E, positive for tumor detected by IHC, size of tumor cell clusters or metastases not stated Stated as N0(i+) with no further information on regional lymph nodes
888	OBSOLETE DATA CONVERTED V0200 See code 987 Not applicable: CS Lymph Nodes not coded 000
987	Not applicable: CS Lymph Nodes not coded 000
988	Not applicable: Information not collected for this case (If this item is required by your standard setter, use of code 988 will result in an edit error.)

CS Site-Specific Factor 4
Immunohistochemistry (IHC) of Regional Lymph Nodes