Breast Flashcards
Normal anatomy
Stroma - fat and fibrous tissue; far predominates
Ductal system containing 6-10 ducts that divide into smaller and smaller ducts, ending at lobules
Ducts drain at the nipple, which is the main excretory duct
The terminal ductal lobular unit is the structural unit of the breast, where pathology is observed
The terminal duct branches into lobules, each comprised of multiple acini –> acini is lined by epithelial and myoepithelial cells (these cells are LOST in carcinomas/malignant lesions, so their presence would indicate a benign lesion if there is some pathology)
The breast reaches full maturity during lactation, and acini proliferate within the lobules and produce milk
How do breast pathologies present?
Pain, lump, discharge or abnormality via ultrasound
30% of these women have NO PATHOLOGY (many lumps are just normal)
40% have FIBROCYSTIC CHANGES (non-neoplastic)
30% have NEOPLASMS, of which 20% are benign and 10% are cancerous
Developmental disorders of the breast
Along the MILK LINE (from axilla to pubis) –> breasts form along these lines
Can have supernumerary nipples or supernumerary breasts along his line (usually axilla or chest)
These are developmental abnormalities and are NOT NEOPLASMS
Inflammatory diseases of the breast
Acute Mastitis –> occurs most often during lactation because CRACKS in nipple may form –> bacterial entry STAPH AUREUS can lead to inflammation or abscess
Patients present with redness, induration, pain –> Treat with antibiotics
Fat necrosis –> usually after trauma/surgery –> causes the fat to LIQUEFY and DIE –> early, we see acute inflammation and liquefactive necrosis of fat;
Later we see macrophages infiltrating, eating the fat –> LIPOPHAGES; the necrotic area is eventually REPLACED BY A FIBROUS SCAR –> firm nodule that can MIMIC a carcinoma, obviously not cancerous
Fibrocystic Changes
MOST COMMON breast disorder –> account for the majority of breast biopsies
Related to HORMONAL IMBALANCES (usually high ESTROGEN –> contraceptives decrease incidence by BALANCING hormones)
Patients present with an often TENDER LUMP, especially premenstrual women, and the lumps are usually MULTIFOCAL and BILATERAL
Non-Proliferative Fibrocystic Changes
CYST formation, fibrosis, adenosis (lots of glands)
NO INCREASE IN CANCER RISK
Cysts are BLUE DOMED, MULTIFOCAL, VARIABLE
Line by APOCRINE METAPLASIA instead of cuboidal epithelial cells
ADENOSIS may also occur –> described as ill-defined mass caused by an increase in the number of acini per lobule
Proliferative Fibrocystic Changes
Sclerosing adenosis, epithelial hyperplasia, small duct papilloma, atypical hyperplasia
INCREASE RISK OF CANCER (1.5 - 2x)
Epithelial hyperplasia - ducts and acini expand in size due to proliferation of the epithelium
SCLEROSING ADENOSIS –> small lesion associated with calcification - detectable by mammography but usually not palpable due to tiny size
Atypical Epithelial Hyperplasia…
ATYPICAL DUCTAL HYPERPLASIA and ATYPICAL LOBULAR HYPERPLASIA –> associated with a MODERATELY increased cancer risk (5x); RARE;
Usually atypical ductal begins a “spectrum” –> followed by DUCTAL CARCINOMA in SITU (malignant but still within the duct)
–> followed by INVASIVE DUCTAL CARCINOMA
Gynecomastia
MALES! Presents as a SUBAREOLAR ENLARGEMENT and can be UNI or BILATERAL
Usually caused by an IMBALANCE of ESTROGEN and ANDROGEN hormones, but can also indicate CIRRHOSIS or a TESTICULAR TUMOR
Most commonly occurs in PUBERTY or the ELDERLY (more likely to have hormonal imbalances)
Microscopically –> proliferation of the connective tissue and ductal epithelium
NO INCREASED RISK OF CANCER
Fibroadenoma
BENIGN TUMOR of the STROMA
Most common tumor of the breast and in young women!
WELL CIRCUMSCRIBED –> bulges over the cut surface; DOES NOT ADHERE to breast tissue around it –> MOBILE MASS
Stromal element –> neoplastic, causes a great deal of FIBROSIS
Epithelial element –> causes ELONGATED and COMPRESSED ducts
Excision is completely curative; NOT a precursor to breast cancer
Increases in size and tenderness with estrogen
Phyllodes Tumor
BENIGN TUMOR of the STROMA; much larger and rarer than fibroadenoma
Usually in OLDER WOMEN, and the mass can be so large that it causes ULCERATION OF OVERLYING SKIN
Well circumscribed, associated with CYST formation
Biphasic –> epithelial component benign, while stromal component is neoplastic and determines tumor grade
Low grade and high grade can BOTH be treated by excision but high grade are LIKELY TO RECUR and become MALIGNANT/METASTASIZE
Large Duct/Intraductal Papilloma
BENIGN EPITHELIAL TUMOR
Presents with BLOODY NIPPLE DISCHARGE
Small, solitary, non-palpable lesion that occurs near the lactiferous ducts, thus causing the discharge
Papilloma fills the ducts, dilates it and may also fill the space with blood
Maintains the lining of the epithelial and myoepithelial cells and may form a WELL-DEFINED myoepithelial layer
SLIGHT increase in risk of cancer (1-2x)
Risk factors for breast cancer
Minority of women have genetic predisposition (BRCA)
Risk increases with age, family history (especially if relative had PRE-menopausal cancer), proliferative fibrocystic changes, having prior breast cancer
Exposure to ESTROGEN –> early menarche and late menopause will INCREASE RISK b/c of more estrogen exposure
Early and multiple births/breast feeding are PROTECTIVE –> pregnancy breaks the cycle and reduces exposure to estrogen
How do breast cancers predominantly metastasize?
VIA LYMPH NODES
Majority of tumors are in the UPPER-OUTER Quadrant of the breast and spread via AXILLARY NODES
Central or inner quadrant tumors spread via the INTERNAL MAMMARY LYMPH NODES
Later in the disease, they can progress HEMATOGENOUSLY
Breast Cancer Classification
NON-INVASIVE (15-30%) –> Ductal Carcinoma in Situ, Lobular Carcinoma in Situ
INVASIVE (75-80%) –> Invasive Ductal (most common), Invasive Lobular, Special Types (medullary, mucinous, tubular)
Ductal Carcinoma in Situ
NON-INVASIVE malignant breast cancer
Proliferation of the DUCTAL cells and is CONFINED to the BASEMENT MEMBRANE OF THE DUCTS
Presents microscopically as a few different patterns –> SOLID (homogenous proliferation), COMEDO (area of central necrosis), CRIBIFORM (hole-punches throughout)
Marked expansion of malignant epithelial cells that display nuclear pleomorphism and mitotic figures
Associated with PLEOMORPHIC CALCIFICATION (this is what we see on mammography, not very palpable)
Treatment can be CURATIVE since it is CONFINED and does not metastasize, but if not taken care of can eventually break through BM and become INVASIVE
