Diseases of the liver and pancreas

Grows as a spherical nodule

Sharply circumscribed

Freely movable from the surrounding breast substance

Frequently occur in the upper outer quadrant of the breast

Size < 1 cm to giant forms 10 to 15 cm in diameter (giant fibroadenoma)

Most are surgically removed when 2 to 4 cm in diameter

On section they are grayish white, and often contain slit-like spaces

Histologic pattern:

Delicate, cellular, fibroblastic stroma resembling intralobular stroma, enclosing glandular and cystic spaces lined by epithelium

Intact, round-to-oval gland spaces may be present, lined by single or multiple layers of cells (pericanalicular fibroadenoma)

In other areas, the connective tissue stroma appears to have undergone more active proliferation with compression of the gland spaces.

In consequence, glandular lumina are collapsed or compressed into slit-like, irregular clefts, and the epithelial elements then appear as narrow strands or cords of epithelium lying with the fibrous stroma (intracanalicular fibroadenoma)

Both pericanalicular and intracanalicular patterns often coexist in the same tumor

Cystosarcoma phyllodes

• Arise from intralobular stroma but may recur or be frankly malignant

• Are much less common than fibroadenomas

• Majority of the tumors behave in a relatively benign fashion

• Distinguished from fibroadenoma on the basis of cellularity, mitotic rate, nuclear pleomorphism, loss of the usual biphasic pattern of stroma and associated benign epithelium, and infiltrative borders

• Low-grade tumors are

• Seen most commonly

• May recur locally

• Only rarely metastasize

• High-grade lesions

• Rare

• Behave aggressively

• Local recurrences common

• Distant hematogenous metastases

• Lymph node metastases are rare as with other sarcomas

• Size variable: Few centimeters to massive lesions involving the entire breast.

• Larger lesions often are lobulated owing to the presence of nodules of proliferating stroma lined by epithelium (phyllodes is Greek for leaf-like)

• Histologically:

• Lower grade lesions resemble fibroadenomas but with increased cellularity and mitotic figures.

• High-grade lesions may be difficult to distinguish from other types of soft tissue sarcomas

Carcinoma of the Breast
Incidence and Epidemiology

• Rare before the age of 25 except in certain familial cases

• May occur at any age thereafter, with a peak incidence at or after the menopause.

• Geographic influences: Five times more common in the United States than in Japan and Taiwan.

• Genetic predisposition:

  • Well defined

  • Magnitude of risk is in proportion to

    • Number of close relatives with breast cancer

    • Age when cancer occurred in relatives

  • The younger the relatives at the time of development of cancer and the more bilateral cancers, the greater the genetic predisposition

• Increasing age: Uncommon before age 25, but then a steady rise to the time of menopause, followed by a slower rise throughout life.

• Length of reproductive life: Risk increases with early menarche and late menopause.

• Parity: More frequent in nulliparous than in multiparous women.

• Age at first child: Increased risk when older than 30 years of age at time of first child.

• Obesity: Increased risk attributed to synthesis of estrogens in fat depots.

• Exogenous estrogens: Moderately increased risk with high-dosage therapy for menopausal symptoms.

• Oral contraceptives: No clear-cut increased risk; attributed to balanced content of estrogens and progestins in currently used oral contraceptives.

• Fibrocystic changes with atypical epithelial hyperplasia: Increased risk, as noted in earlier discussion of this condition.

• Carcinoma of the contralateral breast or endometrium: Increased risk.

Classification and Distribution

• Is more common in the left breast than in the right

• ~50% arise in the upper outer quadrant

• 10% in each of the remaining quadrants

• ~20% in the central or subareolar region

• WHO classification of histologic tumor types:

• Noninvasive

• 1a. Intraductal carcinoma

• 1b. Intraductal carcinoma with Paget’s disease

• 2. Lobular carcinoma in situ

• Invasive (infiltrating)

• 1a. Invasive ductal carcinoma–not otherwise specified (NOS)

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