Accessory breast tissue is a normal variant and can present as a mass anywhere along the course of the embryologic mammary streak (axilla to the inguinal region).
Found in 2-6% of women
Most women are unaware that they have accessory breast tissue until they get a mammogram and are told about it. Discomfort, pain, milk secretion, and local skin irritation can occur. Accessory breast tissue responds to hormonal stimulation and may become more evident during menarche, pregnancy, or lactation. On examination supranumerary nipples may also be seen.
This tissue ranges from a small focus of parenchyma to complete structures that include a nipple and an areola.
It is also important to remember that both benign and malignant diseases of breast tissue in ectopic locations in adult women have been described.
Accessory breast tissue can be found anywhere along the milk line (embryologic mammary streak) but are most frequently found in the axilla .May be bilateral.
Various disorders associated with supernumerary nipples, including:
- urogenital defects
- vertebral abnormalities
- hypertrophic pyloric stenosis
- testicular cancer
- aberrant ventricular conduction
Most accessory breast tissue is found coincidentally on routine screening mammography. See case 18719.
Ultrasound imaging shows breast tissue which is indistinguishable from that of the regular breast.
Occasionally performed in challenging atypical cases but in practcie this is rarely needed. The signal and enhancement characteristics are similar to normal glandular tissue.
Treatment and prognosis
No treatment is required in the vast majority of cases. The treatment of choice for symptomatic accessory axillary breast tissue is surgical excision as removal of the tissue will relieve physical discomfort or mechanical discomfort in the case of large volume accessory tissue.
Accessory breast tissue should also be monitored for pathologic changes such as malignancy, fibroadenoma, mastitis and fibrocystic changes and therefore undergo the same screening as normal breast tissue.
This rarely presents a diagnostic dilemma. In every day senology this is a casual observation which stays stable over time. As mentioned above all disease of the breast also occur in accessory breast tissue.
- 1. Laor T, Collins MH, Emery KH et-al. MRI appearance of accessory breast tissue: a diagnostic consideration for an axillary mass in a peripubertal or pubertal girl. AJR Am J Roentgenol. 2004;183 (6): 1779-81. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Conant EF, Brennecke CM. Breast imaging, case review. Mosby Inc. (2006) ISBN:0323017460. Read it at Google Books - Find it at Amazon
- 3. Eurorad teaching files : Case 7137 - showing axillary breast tissue
- 4. Paredes ES. Atlas of mammography. Lippincott Williams & Wilkins. (2007) ISBN:0781764335. Read it at Google Books - Find it at Amazon
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Accessory mammary tissue||✗|
|Supernumerary breast tissue||✗|