Benign Breast Conditions

Question 1

Describe the normal breast tissue

Answer 1

• variably fibrous/fatty interlobular stroma
• lactiferous ducts
• glandular tissue (attached to ductal tree) where the milk is made
• glands and ducts lined by 2 layered epithelium: inner luminal layer and outer myoepithelial layer

Question 2

What aids a clinical diagnosis of breast disease?

Answer 2

• clinical examination
• imaging (x-ray, mammography, ultrasound, MRI)
• needle biopsy

Question 3

What are the different types of benign breast condition?

Answer 3

• developmental (eg. Ectopic breast tissue)
• inflammatory (eg. Mastitis, granulomatous, inflammatory breast cancer)
• fibrocystic change
• stromal changes (eg. Stromal overgrowth - diabetic fibrous mastopathy, PASH)
• benign neoplasms (eg. Fibromadenoma)

Question 4

Describe Heterotopic breast tissue

Answer 4

• ectopic breast tissue most often on the ‘milk-line’ between the axilla and groin
• nipple-areolar and glandular tissue may be present together or individually

Question 5

Describe the changes to breast tissue during and after lactation

Answer 5

• during: lumen is dilated from milk production
• after: involution from wave of cell deletion in the glandular tissue through apoptosis back to almost pre-pregnancy state

Question 6

Describe stromal overgrowth

Answer 6

• usually begins at puberty or during pregnancy
• mild asymmetry only requires reassurance
• severe asymmetry may require corrective surgery
• nipple inversion is common (but new nipple inversion warrants investigation)

Question 7

Describe acute mastitis

Answer 7

• a cellulitis associated with breast feeding
• skin fissuring (breakdown of the skin) allows bacteria to enter
• stasis of milk favours bacterial growth leading to infection
• abscesses can form which may require incision and drainage

Question 8

Describe granulomatous inflammation

Answer 8

Can be associated with systemic conditions eg. Sarcoidosis, and infections eg. TB

Question 9

Describe idiopathic granulomatous mastitis

Answer 9

• lobule centred non-necrotising granulomatous inflammatory process
• tends to recur after excision (may response to steroids)

Question 10

What are recurrent subareolar abscesses associated with?

Answer 10

• mammillary fistula or squamous metaplasia of lactiferous ducts
• smoking

Question 11

Describe periodical mastitis/duct ectasia

Answer 11

• inflammation and dilation of central lactiferous ducts
• periductal chronic inflammation and scarring
• can be asymptomatic, discomfort, mass, nipple retraction/inversion
• mammogram: calcified luminal secretions
• associated with smoking

Question 12

Describe fibrocystic changes in breast tissue

Answer 12

• include small and large cysts, increased amounts of glandular tissue (adenosis), increased fibrous stroma, epithelial hyperplasia with/without atypia, apocrine metaplasia of cyst epithelium common
• atypia confers an increased risk of breast cancer
• papillomas, papillomatosis and radial scards part of spectrum of fibrocystic change
• either non-proliferative, proliferative without atypia or proliferative with atypia

Question 13

How is apocrine metaplasia recognised on histology?

Answer 13

• large rounded epithelial cells
• granular eosinophilia cytoplasm and apical projections
• does not increase cancer risk

Question 14

What are the 2 lobular neoplastic conditions and their markers?

Answer 14

• atypical lobular hyperplasia
• lobular carcinoma in situ
• does not progress to invasive cancer but both increase cancer risk
• marked by microcalifications on mammography, columnar cell change and hyperplasia (with/without atypia)
• atypia requires further investigation to exclude invasive/in situ malignancy

Question 15

Describe radial scars and their associations

Answer 15

• benign lesions with a fibrotic core and elastic fibres
• contains trapped glands and a pseudo-infiltrate even appearance
• associated with atypical proliferation (cancer risk) which can be seen on mammography

Question 16

Describe intraduct papilloma and papillomatosis

Answer 16

• benign tumour of epithelium lining the mammary ducts
• solitary central papillomas are non-problematic if no epithelial atypia
• sometimes presents with bleeding from nipple
• multiple papillomas (papillomatosis) increase risk of malignancy

Question 17

Describe diabetic fibrous mastopathy

Answer 17

• stromal fibrosis with infiltrating lymphocytes
• associated with type I diabetes
• may present with hard mass (clinical suspicion of carcinoma)
• more common in women

Question 18

Describe pseudo-angiomatous stromal hyperplasia (PASH)

Answer 18

• proliferation of myofibroblasts
• may cause mass which might require biopsy to exclude malignancy
• cause unknown

Question 19

Describe fibroadenomas

Answer 19

• characteristic overgrowth of epithelium and stroma resembling a giant lobule
• firm, tender, mobile mass
• sensitive to hormones

Question 20

Describe Phyllodes tumour

Answer 20

• combines epithelium and mesenchyme, with more cellular stroma, mitotic activity, cytological atypia and infiltrative border than fibroadenomas
• resemble fibroadenomas with a tendency for local recurrence
• require surgery with a margin of normal breast tissue

Question 21

What is a pure adenoma?

Answer 21

A fibroadenomas that lacks the prominent stromal element

Question 22

What condition mimics Paget’s disease of the nipple?

Answer 22

• nipple adenoma (papillomatosis of nipple ducts/erosive adenomatosis)
• biopsy may be required to exclude malignancy

Question 23

Describe a hamartoma of the breast

Answer 23

• discrete smooth painless mass
• glandular, fatty and fibrous connective tissue
• benign and can be identified on mammography