Benign Breast Pathology

Question 1

Describe the cytological rating system for breast tissue

Answer 1

Coded from C1 to C5

C1: inadequate sample, C2: benign, C3: atypia, C4: suspicious of malignancy, C5: malignant

Question 2

Describe normal breast histology

Answer 2

Ductal lobular system lined by inner glandular epithelium

Question 3

State the symptoms of acute mastitis

Answer 3

Painful, red breast, fever

Question 4

Describe the pathophysiology of lactational acute mastitis

Answer 4

Polymicrobial staphylococcal infection due to cracks in the nipple

Question 5

Describe the pathophysiology of non-lactational acute mastitis

Answer 5

Keratinising squamous metaplasia block lactiferous ducts leading to peri-ductal inflammation and rupture

Question 6

Describe the cytology of lactational acute mastitis

Answer 6

Abundance of neutrophils

Question 7

Describe the management of acute mastitis

Answer 7

Antibiotics +/- surgical drainage

If present, treatment of duct ectasia

Question 8

State the biggest risk factor for mammary duct ectasia, and at least one other risk factor

Answer 8

Main: Smoking
Others: multiparity, age 40-60

Question 9

Define mammary duct ectasia

Answer 9

Inflammation and dilatation of large breast ducts causing a poorly defined palpable periareolar mass with thick, white nipple secretions

Question 10

Describe the cytology of mammary duct ectasia

Answer 10

Proteinaceous material and macrophages

Question 11

Describe the pathophysiology of mammary duct ectasia

Answer 11

Diltation in one or more of the larger lactiferous ducts, which then fill with a stagnant brown or green secretion. The secretion irritates the surrounding tissue leading to periductal mastitis or abscess and fistula formation.

Question 12

Define breast fat necrosis

Answer 12

Inflammatory reaction to damaged adipose tissue

Question 13

Describe the clinical presentation of breast fat necrosis

Answer 13

Painless breast mass or skin thickening (can cause skin tethering or nipple retraction). May be identified on mammogram screening.

Question 14

State at least 3 causes of breast fat necrosis

Answer 14

Trauma, radiotherapy, surgery, nodular panniculitis

Question 15

Describe the histology of breast fat necrosis

Answer 15

Empty spaces, histiocytes, giant cells

Question 16

Describe the clinical presentation of fibroadenoma

Answer 16

Painless breast lump - spherical, freely mobile, rubbery, variable size

Question 17

Describe the histology of fibroadenoma

Answer 17

Multinodular mass of expanded intralobular stroma

Question 18

Describe the cytology of fibroadenoma

Answer 18

Branching sheets of epithelium, bare bipolar nuclei, and stroma

Question 19

Define fibroadenoma

Answer 19

Benign tumour from the overgrowth of collagenous mesenchyme, often multiple and bilateral

Question 20

Define duct papilloma

Answer 20

Benign papillary tumour arising within the duct system of the breast

Question 21

Describe the clinical presentation of duct papilloma

Answer 21

Bloody discharge

Question 22

Describe the cytology of duct papilloma

Answer 22

Discharge cytology shows branching papillary groups of epithelium

Question 23

Describe the histology of duct papilloma

Answer 23

Papillary mass within a dilated duct lined by epithelium

Question 24

Define radial scar

Answer 24

A benign sclerosing lesion of central scarring surrounded by proliferating glandular tissue in a stellate pattern

Question 25

State two benign conditions which mimic breast cancer on mammography

Answer 25

Radial scar, mammary duct ectasia

Question 26

Describe the histology of radial scar

Answer 26

Central, fibrous, stellate area

Question 27

Define Phyllodes tumour

Answer 27

Tumour of the interlobular stroma with increased cellularity and mitoses. Can be low or high grade

Question 28

When and how does Phyllodes tumour present?

Answer 28

Age >50 years with a palpable mass

Question 29

Name three proliferative benign breast lesions

Answer 29

Usual epithelial hyperplasia, flat epithelial atypia, in situ lobular neoplasia

Question 30

Describe usual epithelial hyperplasia

Answer 30

Growth of glandular tissue and epithelial cells forming fronds, not considered a precursor to cancer (although slightly increased risk)

Question 31

Describe flat epithelial atypia

Answer 31

Multiple layers of epithelial cells with more regular, round lumens with punched out areas. 4x increased risk of cancer

Question 32

How much does in situ lobular neoplasia increase the risk of breast cancer?

Answer 32

7-12x

Question 33

Describe the histology of in situ lobular neoplasia

Answer 33

Solid proliferation of aplastic cells with little space and small residue areas of lumen