Breast Disease Flashcards
Breast Anatomy
- modified sweat gland
- function unit -> terminal duct lobular unit (TDLU)
- Most TDLUs that are close in proximity empty into the same lactiferous duct
- lactiferous ducts proceed toward the nipple, increasing in size the closure they get; others coalesce with each other
- lactiferous duct –> lactiferous sinuses
- each duct surrounded by specialized stroma - intralobular stroma
- rest of the breast is interlobular stroma - made of adipose and soft tissue
- many lesions arise from these structures
Breast Histology
- TDLUs have rounded contours - surrounded by the intralobular stroma
- the inner layer of epithelial cells is what undergoes a cancerous malignant change
- TDLUs - central lumen (surrounded by an inner layer of epithelial cells that make the breast milk, myoepithelial cells surround the epithelial cells, further surrounded by layers of basement membrane
- cancer - in situ (inner layer surrounded by myoepithelial cells and basement layers) and invasive (not surrounded by myoepithelial cells and basement layers)
Clinical Presentations of Breast Disorders
- palpable mass
- lumpiness (w/o discreet mass)
- Pain
- Nipple discharge
- Mammographic abnormality
A sampling of Breast Disorders
- Nipple Discharge (smear, yield low)
- Fine needle aspiration biopsy (mass or mammogram abnormality)
- Core biopsy (with or w/o image guiding, most common method)
- Breast Duct excision
- Lumpectomy/Partial Mastectomy - with prior diagnostic
- Mastectomy
Interlobular Stroma
Fat necrosis
- most common arising lesion in IS
- can mimic cancer
- firm, irregular mass, (+/-) erythema overlying skin, skin retraction and dimpling - usually superficial and potentially from trauma
- consists of histocytes, small lymphocytes, multinucleated giant cells or histocytes
Benign mesenchymal tumours
Malignant mesenchymal Tumours/sarcomas
Nipple, Large Lactiferous ducts and sinuses
Acute Mastitis
- most common during lactation (early on)
- fissures and breast engorgement predispose
- usually staph, strep - bacterial
- Tense, hot, painful breast, +/- enlarged, tender axillary lymph nodes
- potential abscess formation - healing by fibrosis -> mimicked cancer appearance with fixation
- treatment -> antibiotics, skin care, continuing pump/breastfeeding to relieve engorgement, may require drainage
Intraductal papillary lesions
- 30s-50s
- bloody nipple discharge or palpable areolar mass (rare)
- treatment -> local excision
- benign, can do a malignant transformation
Duct ectasia
Squamous metaplasia of lactiferous ducts
subareolar abscess
Nipple Adenoma
Paget’s disease of the nipple
Intralobular Stroma
Fibroadenoma (epithelial component)
- women 20s-30s
- discrete, mobile, usually non-tender
- no dimpling or retraction of the overlying skin
- rounded/lobulated contour
- rubbery-to-firm texture, may calcify
- stromal and epithelial components
- No atypia, few stromal mitoses
- left in situ and monitored (sometimes excision)
- microscope - biphasic lesion, neoplasm comprised of the spindly stromal component, with inner epithelial elements - no overgrowth, atypia, increased stromal activity, floyd tumor more aggressive counter part
Phyllodes Tumour
PASH
Terminal Duct Lobular Unit
Fibrocystic Disease
- palpable breast masses that fluctuate with the menstrual cycle and may be associated with pain/tenderness
- common finding, most often representing physiological changes rather than pathological
- cysts, fibrosis, apocrine metaplasia, mild “usual” epithelial hyperplasia (benign proliferation of epithelium)
Proliferative changes without atypia
Proliferative changes with Atypia (atypical hyperplasia)
in situ carcinoma
Invasive Carcinoma
Epithelial Breast Lesions and Risk of Developing Invasive Carcinoma
Non-Proliferative lesions - the risk of malignancy = x1, no increased risk of cancer
- Fibrocystic change
- Duct ectasia (widen/thickens)
- Cysts
- Apocrine change
- Fibroadenoma
Proliferative lesions without Atypia - the risk of malignancy = x1.5-2, benign but increased risk of cancer
- Mod/florid epithelial hyperplasia
- Papilloma
- Sclerosing Adenosis (ducts cancer)
- Radial scar/complex sclerosing lesion
- Complex Fibroadenoma
Atypical Hyperplasia - risk of malignance = x4-5, risk with FamHx + AH = x9-10
- Atypical ductal hyperplasia
- Atypical lobular hyperplasia
Breast Cancer Epidemiology and Risk Factors
- 1/8 females in NA
Epidemiology/Risk Factors:
- age and sex (F>M, 75% are 50+)
- family history (80% sporadic, 20% familial) - BRACA 1/2 (high and medium penetrance)
- Geographic Factors (NA, Euro >)
- Race/ethnicity (early menarche, nulliparity (never been pregnant), no Breastfeeding, older age at 1sty pregnancy)
- Reproductive history
- Ionizing radiation
- Other: obesity, hormone replacement, mammographic density, EtOH
Classification of Cancer - In situ
- carcinoma confined to ducts and lobules by an intact myoepithelial cell layer
- has not penetrated the basement membrane
- within TDLUs, malignant cells fill and expand the ducts and lobules - still confined to ducts and lobules
- intact myoepithelium and basement membrane
Ductal Carcinoma In Situ (DCIS)
- involves the ducts (can with lobules too)
- Often linear/casting/pleomorphic calcification of mammography; sometimes nipple discharge
- complete excision with negative margins - lumpectomy/mastectomy
- a precursor for invasive cancer
- high risk of recurrence or invasive CA
Lobular Carcinoma In Situ (LCIS)
- involves the lobules (can with ducts too)
- Usually found incidentally on breast performed for another reason; no good clinical, anatomical or mammographic correlate
- Close clinical monitoring and radiographic follow-up
- Non-obligate precursor for cancer
Invasive Mammary Carcinoma
- invasive ductal carcinoma (no special types)
- special types: Tubular, Cribriform, Mucinous, Medullary, Papillary, Lobular, Metaplastic
IMC of No Special Type
- comprises 80% of IMC
- gross features - poorly defined mass, stellate/”crab-like”, gritty
- microscope - malignant cells invade the stroma
- Graded based on tubule/gland formation, degree of nuclear atypia, and mitotic rate - high grade cancer if it does not look like normal breast tissue
IMC of Special Type
- 20% IMC incidence
- recognized using special morphology
- most indicate a favourable prognosis than NST IMC = lower % of distant metastasis, and better survival
- Metaplastic lobular is an exception - worse prognosis
Two Unique Clinical-Pathological Manifestations of Breast Cancer:
- Paget’s Disease of the Nipple
- Inflammation Carcinoma
