Page 773 - Textbook of Pathology, 6th Edition

hyperplasia of usual type and may show various grades of risk to develop invasive breast cancer later. This risk is further 757
epithelial proliferations (mild, moderate and atypical) as more if there is a history of breast cancer in the family.
under, while lobular hyperplasia involving the ductules or
acini is always atypical: GYNAECOMASTIA (HYPERTROPHY OF MALE BREAST)
1. Mild hyperplasia of ductal epithelium consists of at Unilateral or bilateral enlargement of the male breast is
least three layers of cells above the basement membrane, known as gynaecomastia. Since the male breast does not
present focally or evenly throughout the duct. contain secretory lobules, the enlargement is mainly due to
2. Moderate and florid hyperplasia of ductal type is proliferation of ducts and increased periductal stroma.
associated with tendency to fill the ductal lumen with Gynaecomastia occurs in response to hormonal stimulation,
proliferated epithelium. Such epithelial proliferations into mainly oestrogen. Such excessive oestrogenic activity in
the lumina of ducts may be focal, forming papillary males is seen in young boys between 13 and 17 years of age
epithelial projections called ductal papillomatosis, or may (pubertal gynaecomastia), in men over 50 years (senescent
be more extensive, termed florid papillomatosis, or may fill gynaecomastia), in endocrine diseases associated with
the ductal lumen leaving only small fenestrations in it. increased oestrogenic or decreased androgenic activity e.g.
3. Of all the ductal hyperplasias, atypical ductal hyper- in hepatic cirrhosis, testicular tumours, pituitary tumours,
plasia is more ominous and has to be distinguished from carcinoma of the lung, exogenous oestrogen therapy as in
intraductal carcinoma (page 760). The proliferated carcinoma of the prostate and testicular atrophy in
epithelial cells in the atypical ductal hyperplasia partially Klinefelter’s syndrome (secondary gynaecomastia); and lastly,
fill the duct lumen and produce irregular microglandular enlargement without any obvious cause (idiopathic gynaeco-
spaces or cribriform pattern. The individual cells are mastia).
uniform in shape but show loss of polarity with indistinct
cytoplasmic margin and slightly elongated nuclei. MORPHOLOGIC FEATURES. Grossly, one or both the
4. Atypical lobular hyperplasia is closely related to male breasts are enlarged having smooth glistening white
lobular carcinoma in situ (page 761) but differs from the tissue.
latter in having cytologically atypical cells only in half of Microscopically, there are 2 main features:
the ductules or acini. 1. Proliferation of branching ducts which display CHAPTER 25
epithelial hyperplasia with formation of papillary
SCLEROSING ADENOSIS. Sclerosing adenosis is benign projections at places.
proliferation of small ductules or acini and intralobular 2. Increased fibrous stroma with, myxoid appearance.
fibrosis. The lesion may be present as diffusely scattered
microscopic foci in the breast parenchyma, or may form an
isolated palpable mass which may simulate an infiltrating BREAST TUMOURS
carcinoma, both clinically and pathologically.
Tumours of the female breast are common and clinically The Breast
Grossly, the lesion may be coexistent with other significant but are rare in men. Among the important benign
components of fibrocystic disease, or may form an isolated breast tumours are fibroadenoma, phyllodes tumour
mass which has hard cartilage-like consistency, (cystosarcoma phyllodes) and intraductal papilloma.
resembling an infiltrating carcinoma. Carcinoma of the breast is an important malignant tumour
Microscopically, there is proliferation of ductules or acini which occurs as non-invasive (carcinoma in situ) and invasive
and fibrous stromal overgrowth. The histologic cancer with its various morphologic varieties.
appearance may superficially resemble infiltrating
carcinoma but differs from the latter in having maintained FIBROADENOMA
lobular pattern and lack of infiltration into the surrounding Fibroadenoma or adenofibroma is a benign tumour of fibrous
fat. and epithelial elements. It is the most common benign
tumour of the female breast. Though it can occur at any age
Prognostic Significance during reproductive life, most patients are between 15 to 30

Since there is a variable degree of involvement of epithelial years of age. Clinically, fibroadenoma generally appears as
and mesenchymal elements in fibrocystic change, following a solitary, discrete, freely mobile nodule within the breast.
prognostic implications may occur: Rarely, fibroadenoma may contain in situ or invasive lobular
1. Simple fibrocystic change or nonproliferative fibrocystic changes or ductal carcinoma, or the carcinoma may invade the
of fibrosis and cyst formation do not carry any increased risk fibroadenoma from the adjacent primary breast cancer.
of developing invasive breast cancer. MORPHOLOGIC FEATURES. Grossly, typical fibro-
2. Identification of general proliferative fibrocystic changes are adenoma is a small (2-4 cm diameter), solitary, well-
associated with 1.5 to 2 times increased risk for development encapsulated, spherical or discoid mass. The cut surface
of invasive breast cancer. is firm, grey-white, slightly myxoid and may show slit-
3. Multifocal and bilateral proliferative changes in the breast pose like spaces formed by compressed ducts. Occasionally,
increased risk to both the breasts equally. multiple fibroadenomas may form part of fibrocystic
4. Within the group of proliferative fibrocystic changes, disease and is termed fibroadenomatosis. Less commonly,
atypical hyperplasia in particular, carries 4 to 5 times increased