Skip metastases to the axillary lymph nodes in breast cancer refer to the uncommon phenomenon in which metastases do not follow the conventional stepwise pattern from level I to level II, to level III (infraclavicular), to the supraclavicular fossa, and or internal jugular chain 1-6,9.
On this page:
Terminology
Axillary lymph nodes are surgically divided according to their location relative to the pectoralis minor muscle:
- level I: lateral and inferior.
- level II: underneath the muscle.
- level III (infraclavicular): medial and superior.
Rotter nodes are located between the pectoralis major and minor muscles and are considered at level II.
It is widely accepted that the malignant infiltration of axillary lymph nodes follows this sequence, to supraclavicular fossa and or internal jugular chain.
Epidemiology
Skip metastases to the axillary lymph node in breast cancer has been reported to happen in 1.3% to 14.6% of patients in some series 1-6,9.
In the review of four series 1,5,6,9, 1576 patients had axillary lymph node metastases, of this, 74 had skip metastases, with the most frequent pattern: level I skipped to level III (22), level I skipped to supraclavicular (18), and when level I was not affected the most frequent metastasis was to level II (15 patients).
Radiographic features
Ultrasound
The modality of choice for evaluating the axilla, when scanning is safe to stop if the first level is free of disease; and if it is abnormal, because the eighth edition of The American Joint Committee on Cancer staging manual considers level I and II together you can go for the infraclavicular level instead of level II. Stage IIIC includes positive lymph nodes in the infraclavicular fossa (level III), or internal mammary chain plus axilla, or supraclavicular nodes, thus cannot be missed in the evaluation 7,8.
As good practice, you can examine the infra (III) and supraclavicular fossa if the level I nodes are suspicious. You should never forget to scan the internal mammary nodal basins.
Practical points
In a study of 539 cases treated with total axillary dissection, Veronesi et. al 1, stated that the predictive value of the first level is considerable; when lymph nodes at level one are negative, the probability that infiltrating nodes are present at the second and third levels is minimal. When the nodes at the first level are positive, the chances that metastases are also present at the higher levels are of the order of 40% 1.
Unable to process the form. Check for errors and try again.