Accessory breast tissue is a relatively common congenital condition in which abnormal accessory breast tissue is seen in addition to the presence of normal breast tissue. This normal variant can present as a mass anywhere along the course of the embryologic mammary streak (axilla to the inguinal region).
- chest wall
- lateral thigh
Found in 2-6% of women and 1-3% of males 5. Most often though present since birth the patients are not aware of it till puberty.
Most women are unaware about it and it is detected incidentally on a mammogram. Discomfort, pain, milk secretion, thickening of axilla 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 thoracoabdominal region of the milk line (embryologic mammary streak) but are most frequently found in the axilla. May be bilateral. Very rarely seen in the face, back and thigh.
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.
Ultrasound imaging shows breast tissue which is indistinguishable from that of the regular breast.
Occasionally performed in challenging atypical cases but in practice 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. The ectopic breast tissue has been found to have a higher propensity to develop malignancy and occurs at an earlier age. Excessive breast growth (macromastia) can be seen in pregnancy as well as during adolescence.
- thoracic skeleton
- thoracic cage
- thoracic spine
- muscles of the thorax
- intercostal space
- intercostal muscles
- variant anatomy
- spaces of the thorax
- tracheobronchial tree
bronchopulmonary segmental anatomy
- left lung
- right lung
- variant anatomy
- lung parenchyma
- bronchopulmonary segmental anatomy
- cardiac chambers
- heart valves
- pectinate muscles
- cardiac fibrous skeleton
- coronary circulation
- innervation of the heart
- nipple-areola complex
- terminal ductal lobular unit
- axillary tail
- mammary fat
- Montgomery glands
- Cooper ligaments
- Chassaignac bursa
- lymphatic drainage
- blood supply of the thorax
thoracic aorta (development | variant anatomy)
- aortic annulus
- left main coronary artery
- right coronary artery
- congenital anomalies
- sinotubular junction
- aortic root
- brachiocephalic trunk
- common carotid artery
- subclavian artery
- variant anatomy
- aortic isthmus
- descending aorta
- ascending aorta
- pulmonary trunk
- thoracic aorta (development | variant anatomy)
- superior vena cava (cavo-atrial junction | variant anatomy)
- inferior vena cava
- coronary veins
- pulmonary veins
- innervation of the thorax
- 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
- 5. Patel PP, Ibrahim AM, Zhang J et-al. Accessory breast tissue. Eplasty. 2012;12: ic5. Free text at pubmed - Pubmed citation
- 6. Guray M, Sahin AA. Benign breast diseases: classification, diagnosis, and management. Oncologist. 2006;11 (5): 435-49. Oncologist (full text) - doi:10.1634/theoncologist.11-5-435 - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Accessory mammary tissue||✓|
|Supernumerary breast tissue||✓|
|ectopic breast tissue||✓|