Benign Conditions of the Breast

Question 1

Briefly describe the normal anatomy of the breast

Answer 1

• Mammary glands consisting of a series of ducts and secretory lobules (15-20). Ducts are lined by 2 epithelial layers: Inner (luminal) and outer (myoepithelial). Ducts sprout from breast bud and puberty initiates further development.
• Connective tissue stroma which has a fibrous and fatty compounant (role is to attach breast and separate secretory lobules).

Question 2

What is the commonest developmental abnormality of the breast?

Answer 2

Ectopic (heterotopic) breast tissue, most often found on the milk line between the axilla and groin.
- Nipple-areolar and glandular tissue may both be present or one without the other. Any breast disease may occur within ectopic breast tissue

Question 3

What is breast hypoplasia associated with?

Answer 3

• Ulnar-mammary syndrome,
• Turners syndrome,
• Poland’s syndrome.
• Congenital adrenal hyperplasia

Question 4

What can be some common (normal) breast variations

Answer 4

• Mild breast asymmetry,
• Nipple inversion (new nipple inversion may be abnormal)
• Stromal overgrowth leading to macromastia

Question 5

Name some inflammatory conditions of the breast

Answer 5

• Acute/puerperal/lactational mastitis (cellulitis associated with breast feeding)
• Granulomatous inflammation (occurs in systemic disease such as sarcoidosis)
• Inflammatory breast cancer
• Idiopathic granulomatous mastitis (non-necrotising granulomatous inflammation which tends to reoccur. May respond to steroids)
• Foreign body reactions (especially around implants)
• Recurrent subareolar abscesses (may be associated with mamillary fistula)
• Periductal mastitis/duct ectasia (dilatation of central lactiferous duct, periductal chronic inflammation and scarring)
• Fat necrosis which may follow trauma
• Fibrocystic change (most common benign breast condition)

Question 6

Describe features of fibrocystic change in the breast

Answer 6

It is a spectrum of cysts with increased amounts of glandular tissue (adenosis), fibrous stroma and epithelial hyperplasia. Apocrine metaplasia is common (large, rounded epithelial cells), not thought to increase BC risks.
Size varies depending on menstrual cycle

Question 7

What are radial scars?

Answer 7

Part of the fibrocystic change spectrum. They are benign lesions characterised by a fibrotic core with elastic fibres, trapped in glands and a pseudo-infiltrative appearance. The are complex sclerosing lesions if >10mm. Can look like cancers so need excised to rule out

Question 8

Describe the classification of fibrocystic change

Answer 8

• Non proliferative (no excessive risk of BC)
• Proliferative without atypia ( 2 fold increase risk of BC)
• Proliferative WITH atypia (5 fold increase in risk of BC)

Question 9

What is sclerosing adenosis?

Answer 9

Adenosis refers to increase in glandular tissue in breast. It is a proliferative variant of fibrocystic change where there is proliferation of glandular tissue and stroma

Question 10

Name some atypical proliferative fibrocystic changes and their features

Answer 10

• Atypical ductal hyperplasia (features in common with low grade ductal carcinoma in situ. Associated with microcalcifications)
• Lobular neoplasia which includes atypical lobular hyperplasia and lobular carcinoma in situ. Difference between the two is extent and amount of cellular proliferation. They are markers of increased cancer risk.

Question 11

What are columnar cell lesions

Answer 11

Detected on mammograms, they are associated with microcalcifications. Can be columnar cell change/hyperplasia and are recognised with and without atypia. Atypia requires a core needle biopsy

Question 12

What are intraductal papillomas?

Answer 12

Benign tumour of epithelium lining of the mammary ducts. Innocuous if solitary and no epithelial atypia. May present with bleeding from nipple

Question 13

What is papillomatosis?

Answer 13

• Multiple papillomas. They are slightly more likely to be associated with malignancy elsewhere in the same/contralateral breast

Question 14

Name and describe some stromal proliferations

Answer 14

• Diabetic fibrous mastopathy. Stromal fibrosis with infiltrating lymphocytes. Associated with type 1. Presents with hard mass suspicious of cancer.
• Psuedo-angiomatous stromal hyperplasia. Proliferation of myofibroblasts.

Question 15

Name examples of benign neoplasms

Answer 15

• Fibroadenomas
• Phyllodes tumour
• Pure adenoma (lack stromal element seen in fibroadenoma, rare)
• Nipple adenoma
• Hamartoma
• Benign granular cell tumours (rare)

Question 16

Describe features of fibroadenomas

Answer 16

• Benign overgrowth of epithelium and stroma, representing a giant lobules.
• Hormone sensitive
• Usually firm, non-tender and mobile
• can get juvenile fibroadenomas under age 18 which become very large

Question 17

Describe features of a Phyllodes tumour

Answer 17

• Similar to fibroadenoma, combines epithelium and mesenchyme but with more cellular stroma, mitotic activity and cytological atypia with infiltrative boarder.
• They do require surgical excision with margin of normal breast tissue as they are a borderline tumour between benign and malignant

Question 18

Describe features of nipple adenomas

Answer 18

• Benign but can mimic Paget’s disease. Uncommon disease and biopsies are needed to exclude malignancy.

Question 19

What is a hamartoma of the breast?

Answer 19

A discrete smooth painless mass of glandular, fatty and fibrous connective tissue. Usually identified on mammography.