IS Case 438: Intramammary lymph node

Sam McCabe, MD

University of Rochester

Imaging Sciences URMC 2010
Publication Date: 2010-08-30


A 41-year-old asymptomatic female with strong family history of breast cancer in two first-degree relatives presented for high-risk screening breast MRI.


A well-circumscribed, reniform nodule was noted in the posterolateral right breast tissues.


Intramammary lymph nodes are a common finding on breast imaging studies. They are typically less than 5 mm short axis and may lay along the course of a blood vessel. They are most commonly located in the upper outer quadrant, but can be seen in the superior central breast or rarely in the inferior breast. On MRI, lymph nodes demonstrate a low T1 and high T2 signal cortex surrounding a central fatty hilum. Reniform shape and a central fat-containing hilum are diagnostic imaging features on any imaging modality.

Intramammary lymph nodes demonstrate avid enhancement, however typically follow a benign enhancement pattern with a plateau or delayed washout.

Nodal enlargement with effacement of the central hilum in the setting of an ipsilateral breast carcinoma raises concern for neoplastic spread. There are numerous causes of benign breast nodal enlargement, including HIV, rheumatoid arthritis, lupus, sarcoidosis, and regional dermatitis/cellulitis.


  1. Schmidt WA, Boudousquie AC, Vetto JT, et al. Lymph nodes in the human female breast: a review of their detection and significance. Hum Pathol. 2001 Feb;32(2):178-87. PMID: 11230705
  2. Spillane AJ, Donnellan M, Matthews AR. Clinical significance of intramammary lymph nodes. Breast. 1999 Jun;8(3):143-6. PMID: 14965734

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