What is the significance of an intrapulmonary lymph node detected on a breast ultrasound in an adult female?

Intrapulmonary Lymph Node on Breast Ultrasound: Clinical Significance

Direct Answer

An intrapulmonary lymph node detected on breast ultrasound is almost certainly a reporting error or anatomical misidentification, as intrapulmonary lymph nodes exist within lung parenchyma, not breast tissue. The finding likely represents either an intramammary lymph node (a benign normal variant within breast tissue) or possibly an axillary lymph node visualized at the periphery of the ultrasound field.

Understanding the Terminology Error

• Intrapulmonary lymph nodes are located within the lung parenchyma, typically appearing as small triangular subpleural nodules with linear extensions to the pleural surface on CT imaging 1
• These nodes are found along bronchi up to the fourth-order level and are rarely visible on routine imaging 2, 3
• They have no relevance to breast imaging and cannot be detected on breast ultrasound 1

Most Likely Actual Finding: Intramammary Lymph Node

If the report states "intrapulmonary" but the examination was breast ultrasound, the finding is most likely an intramammary lymph node, which is a benign normal variant:

• Intramammary lymph nodes are classified as BI-RADS Category 2 (benign finding) and require no further workup or follow-up 1
• These are normal lymph nodes located within breast parenchyma and can be confidently diagnosed on ultrasound 1
• They typically appear as small, oval, hypoechoic structures with an echogenic fatty hilum 1

Alternative Possibility: Axillary Lymph Node

The finding could represent a normal axillary lymph node captured at the edge of the breast ultrasound field:

• Normal axillary lymph nodes have uniform cortical thickness, preserved fatty hilum, and oval shape 1, 4
• Benign axillary nodes require no intervention unless there is clinical suspicion for malignancy 1
• The American College of Radiology notes that morphologically normal lymph nodes on ultrasound are considered benign 1, 4

Recommended Action

Contact the interpreting radiologist to clarify the terminology and confirm whether the finding represents:

1. An intramammary lymph node (benign, no follow-up needed) 1
2. A normal axillary lymph node (benign, no follow-up needed) 1
3. A true documentation error requiring correction

Clinical Pitfalls to Avoid

• Do not pursue pulmonary imaging (chest CT) based on this report, as breast ultrasound cannot visualize intrapulmonary structures 1
• Do not biopsy a clearly benign intramammary or normal-appearing axillary lymph node 1
• Ensure proper anatomical terminology in the corrected report to prevent future confusion and unnecessary workup

When Further Evaluation IS Needed

Further evaluation would only be warranted if the lymph node demonstrates suspicious features:

• Cortical thickening >3mm, loss of fatty hilum, round shape, or abnormal vascularity pattern would require ultrasound-guided core needle biopsy 1, 4
• In the context of known or suspected breast cancer, morphologically abnormal lymph nodes should undergo tissue sampling 1, 4