Page 538 - Concise Pathology for Exam Preparation ( PDFDrive )

19 The Breast 523

Nonproliferative Breast Changes
Clinically significant disease (lumpy-bumpy breast) without epithelial hyperplasia

Clinical Features
• Presents with an ill-defined lump/nodularity, mammographic densities/calcification or
nipple discharge
• Affects women between 20 and 40 years; peaks at or just before menopause; is rare after
menopause and before adolescence
• Usually multiple and bilateral
• No risk of developing cancer
• Clue to diagnosis is disappearance of the mass after fine needle aspiration of cyst contents

Aetiology

Hormonal imbalance: increased oestrogen and decreased progesterone
Morphology
Three main morphological changes are seen:
• Cystic dilation of ducts and lobules
• Large cysts contain semitranslucent and turbid fluid, which imparts brown to blue
colour to them (blue dome cysts)
• Epithelium lining the cysts is flattened and atrophic; may show apocrine metaplasia
(large polygonal cells that have abundant granular eosinophilic cytoplasm and small
round hyperchromatic nucleus)
• Fibrosis
• Cysts release a secretory material into the stroma, which causes chronic
inflammation and fibrosis with loss of the normal myxomatous appearance.
• Adenosis
• Increase in the number of acini per lobule. The acini are lined by columnar epithelium
which may occasionally show nuclear atypia (labelled “flat epithelial atypia”—a clonal
disorder associated with deletions of chromosome 16q which is thought to be the earli-
est recognizable precursor of low-grade malignancy; however, does not necessarily
translate into an increased risk of invasive breast cancer).
• The acini are enlarged only (as in blunt duct adenosis) or enlarged and distorted
(as in sclerosing adenosis).
• Calcifications may be seen in the lumens.

Proliferative Breast Disease Without Atypia
Proliferative (hyperplastic) changes may be seen in the ductules, terminal ducts and
sometimes the lobules. They are classified into:
(a) Epithelial hyperplasia:
(i) Defined as presence of more than two cell layers in the lining of ducts and
lobules
(ii) Can vary from mild to florid hyperplasia
(iii) The ducts, ductules and lobules are filled with cuboidal cells showing small
glandular pattern called fenestrations.
(b) Sclerosing adenosis:
(i) Less common but significant type of proliferative breast disease because of its
clinical and morphological similarity to invasive carcinoma.
(ii) Characterized by marked intralobular fibrosis and proliferation of small ductules
and acini.
(iii) On gross examination, sclerosing adenosis appears hard and rubbery like invasive
breast carcinoma.
(iv) Histopathology sections show proliferation of epithelial and myoepithelial cells lining
small ducts and ductules. The proliferating glands and ductules appear back to back.
There is marked stromal fibrosis which compresses and distorts the proliferating epi-

mebooksfree.com