Breast Pathology Flashcards
What is the anatomical composition of the breast?
A modified sweat gland adapted for milk production.
How are breast ducts and glands organized?
Into small subdivisions called lobules.
What are the primary components of the breast stroma?
Mostly fat plus a network of thin fibrous ligaments.
What hormones affect breast tissue and how?
Estrogen and progesterone; they account for the increase in size at puberty and changes during the menstrual cycle.
What is the primary lymphatic drainage pathway for the breast?
To the axillary nodes.
Where do lymphatics from the medial aspect of the breast drain?
Into the internal mammary nodes.
What changes occur in the breast during pregnancy?
Milk-secreting cells develop (prolactin-induced) and secretion begins immediately after birth; glandular epithelium atrophies if breastfeeding fails to occur.
What is acute mastitis and what are its common causes?
Acute infection of the breast, typically caused by staphylococcus or streptococcus organisms.
How does staphylococcus infection in the breast typically present?
Produces an abscess.
How does streptococcus infection in the breast typically present?
Produces generalized swelling, tenderness, and pain.
What is chronic breast inflammation often associated with?
Often associated with fibrocystic change.
What is fat necrosis of the breast and what can cause it?
An unusual type of necrosis occurring only in fat, often due to trauma.
What is fibrocystic change in the breast?
Consists of fibrosis, chronic inflammation, and cystic dilation of breast ducts.
What are the classifications of fibrocystic change?
Non-proliferative and proliferative (usual and atypical).
How common is fibrocystic change in women?
50% of women have some degree of fibrocystic change, but only about one-quarter of these patients have any symptoms.
What are the usual characteristics of a fibroadenoma?
A benign neoplastic lesion that is well-circumscribed and encapsulated.
What is a phyllodes tumor and how does it differ from a fibroadenoma?
A spectrum from benign to borderline to malignant, differing in histological features from a fibroadenoma.
What are the differences between fibroadenoma and fibrocystic change?
Fibroadenoma is a well-circumscribed, encapsulated, benign neoplastic lesion; fibrocystic change is a diffuse, non-neoplastic lesion, often cystic and associated with inflammation.
What are the common malignant tumors of the breast?
Invasive ductal carcinoma and invasive lobular carcinoma.
What is the most common subtype of invasive ductal carcinoma?
No specific type (NST).
What is the typical origin of breast cancer?
From the inner lining of breast ducts (ductal carcinomas) or breast lobules (lobular carcinomas).
What are the key epidemiological facts about breast cancer?
The most commonly diagnosed cancer in women worldwide and the 5th leading cause of cancer death.
What are some key risk factors for breast cancer?
Female sex, increasing age, race (higher incidence in Caucasians), increased exposure to estrogen, higher socioeconomic status, significant radiation exposure, family history, BRCA1 & 2 gene mutations, smoking, alcohol intake, sedentary lifestyle, diet.
What are some common clinical presentations of breast cancer?
Small breast lump, breast mass with or without skin changes, peri-areolar eczematous changes, bloody nipple discharge, enlarged breast with signs of inflammation, axillary lump, distant metastases.
What is the “triple test” in diagnosing breast lesions?
Imaging, clinical examination, and biopsy.
What imaging techniques are critical for diagnosing breast disease?
Mammography, ultrasonography, and MRI.
What is the purpose of a vacuum-assisted core biopsy?
To obtain tissue samples for diagnosis.
What are the World Health Organization’s recommendations for mammography screening programs?
It needs to cover at least 70% of the population at risk.
At what age is annual screening mammography recommended for the general population?
Starting at age 40 for the general population.
What is the role of molecular classification in breast cancer?
Guides treatment use and results in targeted use of specific treatments, reducing toxicity.
What are the five IHC markers used for molecular classification of breast cancer?
ER, PR, HER2, CK5/6, EGFR.
What are the biomarker profiles for Luminal A breast cancer?
ER+, PR+, HER2-, Ki67 (<14%).
What are the biomarker profiles for Luminal B breast cancer?
ER+, PR+, HER2+, or ER+, PR+, HER2-, Ki67 (>14%).
What are the biomarker profiles for HER2 breast cancer?
ER-, PR-, HER2+.
What are the biomarker profiles for triple-negative breast cancer?
ER-, PR-, HER2-, CK5/6+, EGFR+.
What are the typical metastasis sites for Luminal A breast cancer?
Most commonly to bone; least likely to brain, liver, or lung.
What treatments are effective for Luminal A breast cancer?
Good response to hormonal therapy.
What are the typical metastasis sites for Luminal B breast cancer?
Most commonly to bone, followed by liver and lung.
What treatments are effective for Luminal B breast cancer?
Benefits from chemotherapy and hormonal therapy.
What are the typical metastasis sites for HER2 breast cancer?
Most commonly to bone, brain, liver, and lung.
What treatments are effective for HER2 breast cancer?
Benefits from chemotherapy and HER2 targeted therapy.
What are the characteristics of basal-like triple-negative breast cancer?
High grade, often affecting younger patients, benefits from chemotherapy.
What gene mutations are commonly associated with the basal phenotype?
BRCA1 mutations.
What is the role of BRCA1 and BRCA2 genes in breast cancer?
Tumor suppressor genes located on chromosomes 17 and 13.
What is the significance of non-lethal genetic damage in carcinogenesis?
It is the basis of excessive cellular proliferation leading to tumorigenesis.
What is clonal expansion in the context of tumorigenesis?
Expansion of a single mutated cell leading to a tumor.
What are the targets of cancer-causing genetic damage?
Specific genes involved in cell proliferation and survival.
What is multistep carcinogenesis?
The process involving multiple genetic mutations leading to cancer.
How does genetic instability contribute to neoplasm development?
Leads to mutation accumulation and tumor development.
What are the cumulative risks of developing breast cancer in BRCA1 and BRCA2 mutation carriers by age 70?
50–70% in BRCA1 carriers and 40-50% in BRCA2 carriers.
What role do normal BRCA genes play in cell proliferation?
Inhibit cell proliferation.
How does germline inheritance of BRCA mutations affect breast cancer risk?
Leads to increased breast cancer risk due to genomic instability.
What happens when there is a loss of heterozygosity in BRCA mutation carriers?
Results in the cessation of growth-inhibiting functions.
How does genomic instability influence cancer development?
Activates checkpoint mechanisms eliminating affected cells.
What specific tissue factors in breast and ovary predispose to cancer in BRCA mutation carriers?
These factors predispose cells to prolonged viability and additional mutations.
How do staph and strep infections in acute mastitis differ in presentation?
Staph usually produces an abscess, while strep produces generalized swelling and tenderness.
What is the significance of the terminal duct lobular unit in breast anatomy?
The functional unit of breast tissue.
What are the key features of chronic breast inflammation?
Often presents with pain and is associated with fibrocystic change.
How does fat necrosis of the breast mimic cancer?
Mimics cancer but is due to trauma.
What is the prevalence of symptomatic fibrocystic change in women?
50% of women experience fibrocystic change, but only one-quarter have symptoms.
What is the difference between non-proliferative and proliferative fibrocystic change?
Non-proliferative has no increased cancer risk; proliferative has increased cancer risk.
What is the increased cancer risk associated with atypical fibrocystic change?
Atypical fibrocystic change has a 5x increased risk of cancer.
How is a fibroadenoma typically diagnosed?
By clinical examination and imaging.
What are the histological features of a fibroadenoma?
Well-circumscribed and encapsulated with proliferating epithelial and stromal elements.
How does a benign phyllodes tumor differ histologically from a fibroadenoma?
Phyllodes tumor can range from benign to malignant and has different stromal characteristics.
What is the significance of encapsulation in a fibroadenoma?
Indicates a benign nature with clear boundaries.
What are the clinical features of invasive lobular carcinoma?
Presents as a breast mass, often with diffuse thickening.
What percentage of breast cancers are invasive ductal carcinoma?
Approximately 70%.
How is breast cancer incidence different across racial and ethnic groups?
Higher incidence in Caucasians.
What lifestyle factors increase breast cancer risk?
Increased exposure to estrogen, higher socioeconomic status, significant radiation exposure.
What dietary factors are associated with increased breast cancer risk?
High fat, high-calorie diets, intake of red meat, and low intake of fruits and vegetables.
What role does family history play in breast cancer risk?
Mutations in BRCA1 & 2, p53, and CHEK2 genes increase risk.
How do mutations in the p53 and CHEK2 genes influence breast cancer risk?
Significantly increase breast cancer risk.
What are common symptoms that indicate breast cancer?
Small lump, skin changes, nipple discharge, axillary lump.
How does mammography contribute to breast cancer diagnosis and management?
Essential for early detection and management.
What are the benefits of mammography in high-risk populations?
Reduces mortality in high-risk populations.
What is the role of ultrasonography in breast cancer diagnosis?
Assists in differentiating solid from cystic masses.
What is the significance of MRI in breast cancer screening?
Provides detailed imaging for complex cases.
How are calcifications assessed in breast biopsies?
To confirm adequate sampling.
What is the purpose of the C5 scoring system in breast cytology?
Assesses the likelihood of malignancy.
What factors contribute to the poor outcomes in male breast cancer?
Due to less frequent diagnosis and often more advanced stage at presentation.
What is the role of exogenous estrogen in breast cancer risk?
Increases risk due to prolonged exposure.
How does postmenopausal obesity contribute to breast cancer risk?
Increases estrogen levels, contributing to risk.
What are the common sites of distant metastases in breast cancer?
Bone, brain, liver, and lung.
How is hormonal therapy used in the treatment of Luminal A breast cancer?
Effective for ER+ and PR+ tumors.
What are the distinguishing features of triple-negative breast cancer?
Lacks hormone receptors and HER2, more aggressive.
How is HER2 targeted therapy used in breast cancer treatment?
Targets HER2-positive cancer cells.
What is the clinical significance of CK5/6 and EGFR in basal-like breast cancer?
Indicative of basal-like subtype, aggressive behavior.
What are the common genetic alterations in basal-like breast cancer?
Commonly involves BRCA1 mutations.
How does CK5/6 positivity influence breast cancer classification?
Indicates a basal-like phenotype.
What are the founder mutations of BRCA1 and BRCA2 in Ashkenazi Jews?
Common mutations increasing breast cancer risk.
How does mutation of caretaker genes contribute to genetic instability?
Leads to genetic instability and increased mutation rate.
What is the role of checkpoint mechanisms in genomic stability?
Eliminate cells with genomic instability.
What factors facilitate the acquisition of mutations in BRCA mutation carriers?
Prolonged cell viability in breast and ovary increases mutation accumulation.
What is the relationship between socioeconomic status and breast cancer risk?
Higher status associated with increased risk.
How does the menstrual cycle influence breast tissue?
Influences cyclical changes in size and sensitivity.
What are the primary imaging modalities used in the staging of breast cancer?
Mammography, ultrasonography, and MRI.
How does hormone replacement therapy affect breast cancer risk?
Increases risk due to prolonged estrogen exposure.
What is the relationship between alcohol intake and breast cancer risk?
Associated with increased breast cancer risk.
How does sedentary lifestyle influence breast cancer risk?
Associated with increased breast cancer risk.
What are the clinical implications of multicentric disease in breast cancer?
Indicates a higher likelihood of recurrence and metastasis.
How is local recurrence managed in breast cancer patients?
Managed with surgery, radiation, and systemic therapies.
