Data Last Updated: Dec. 17, 2025

Lymph Nodes Positive Axillary Level I-II

This input is used for staging

Description

This data item pertains to the number of positive ipsilateral level I and II axillary lymph nodes and intramammary lymph nodes based on pathological information. This data items records the low axillary (level I and intramammary) and mid-axillary (level II, also called interpectoral or Rotter’s nodes). This data item excludes level III (high axillary, also called apical or infraclavicular), internal mammary and supraclavicular lymph nodes. Do not confuse intramammary nodes, which are within breast tissue and are included in level I, with internal mammary nodes, which are along the sternum. This field is based on pathological examination of ipsilateral (same side as the primary cancer) level I and II axillary lymph nodes, so pathological information is included even if the patient had neoadjuvant therapy prior to lymph node removal. Do not include lymph nodes containing only isolated tumor cells (ITCs—metastases less than 0.2 mm in size) in the count of positive nodes.

Rationale

Lymph Nodes Positive Axillary Level I-II can be collected by the surveillance community for breast cancers. Prior to 2018, Breast SSF#3 was used for Lymph Nodes Positive Axillary Level I-II.

Additional Info

**Required for Staging:** EOD only **Source documents:** pathology report

Notes

**Note 1:** **Physician Statement** * Physician statement of number of positive ipsilateral Level I-II axillary nodes can be used to code this data item, when no other specific information is available. **Note 2:** **Axillary Level I and II lymph nodes** * Include only the number of positive ipsilateral level I and II axillary lymph nodes and intramammary lymph nodes in this field. Intramammary nodes, located within the breast, are not the same as internal mammary nodes, located along the sternum. **Note 3:** **Microscopic confirmation** * This field is based on microscopic information only. If no ipsilateral axillary nodes are examined, or if an ipsilateral axillary lymph node drainage area is removed but no lymph nodes are found, code X9. **Note 4:** **Isolated tumor cells** * Lymph nodes with only isolated tumor cells (ITCs) are not counted as positive lymph nodes. Only lymph nodes with metastases greater than 0.2 mm (micrometastases or larger) should be counted as positive. If the pathology report indicates that axillary nodes are positive, but size of the metastases is not stated, assume the metastases are greater than 0.2 mm and code the lymph nodes as positive in this field. **Note 5:** **Positive Axillary lymph nodes compared to Regional Nodes Positive** * When positive ipsilateral axillary lymph nodes are coded in this field, the number of positive ipsilateral axillary lymph nodes must be less than or equal to the number coded in Regional Nodes Positive (i.e., the number of positive ipsilateral axillary nodes will always be a subset of the number of positive regional nodes.) **Note 6:** **Neoadjuvant Therapy:** * If clinical nodal involvement is more extensive, include only those nodes that are positive during clinical workup * Positive nodes can be from an FNA, core biopsy or sentinel lymph node biopsy * ***Example:*** Patient with positive FNA of axillary lymph node, neoadjuvant therapy administered. Lymph node dissection revealed negative lymph nodes. Code X6 for the positive FNA. * If the post-neoadjuvant nodal involvement is more extensive, include only those nodes positive during surgery * Positive nodes can be from an FNA, core biopsy, sentinel lymph node biopsy or lymph node dissection * ***Example:*** Patient with large breast mass, lymph node negative on clinical exam. Neoadjuvant therapy administered. Mastectomy and sentinel lymph node biopsy done, 1 of 2 SLN’s positive. Code 01.

Coding Guidelines

**1)** **Code 00** when all level I and II axillary lymph nodes are negative on pathological examination **2)** **Code 01-99** for the exact number of positive nodes for levels I and II **3)** **Code X1** if more than 99 level I and II axillary lymph nodes are positive **4)** **Code X5** if level I and II axillary lymph nodes were positive, but the number is not specified **5)** **Code X6** if there was only a positive aspiration of level I or II axillary lymph node(s) **6)** **Code X9** when * No axillary nodes were examined * Axillary dissection was performed but no axillary lymph nodes were found * Clinical diagnosis only (no axillary lymph nodes were removed) * Unknown whether axillary lymph nodes are positive
Code Description
00 All ipsilateral axillary nodes examined negative
01-99 1 - 99 nodes positive
(Exact number of nodes positive)
X1 100 or more nodes positive
X5 Positive nodes, number unspecified
X6 Positive aspiration or needle core biopsy of lymph node(s)
X8 Not applicable: Information not collected for this case
(If this item is required by your standard setter, use of code X8 will result in an edit error.)
X9 Not documented in medical record
Level I-II axillary nodes not assessed or unknown if assessed