Breast Pathology Flashcards
Principal mammographic signs of breast carcinomas
Densities and calcifications
Clinical presentation of acute mastitis
Typically occurs during 1st month of breastfeeding, caused by local bacterial infection — usually S.aureus
Breast is erythematous and painful, fever is often present; complications include abscess or cellulitis
Inflammatory condition that presents with painful erythematous subareolar mass that clinically appears to be a bacterial abscess, and is much more common in smokers; may cause inverted nipple
Squamous metaplasia of lactiferous ducts
Inflammatory condition characterized by palpable areolar mass often associated with thick, white nipple secretions and occasionally skin retraction (no pain or erythema); tends to occur in 5-6th decade in multiparous women
Duct ectasia
Clinical manifestations of fat necrosis of breast
Painless palpable mass, skin thickening or retraction, or mammographic densities or calcifications (may mimic cancer)
50% have hx of breast trauma or surgery
Inflammatory condition that presents with single or multiple hard palpable masses or mammographic densities with dense collagenized stroma, and is most common in women with T1DM or autoimmune thyroid disease
Lymphocytic mastopathy
Nonproliferative breast changes are not associated with increased risk of breast cancer. What are the 3 principle nonproliferative changes?
Cystic change, often with apocrine metaplasia — contain turbid, semitranslucent brown/blue fluid (blue dome cysts); dx is confirmed by disappearance of mass after FNA of contents
Fibrosis — chronic inflammation and fibrosis result from ruptured cyst contents
Adenosis — increase in number of acini per lobule that may appear benign or show flat epithelial atypia; calcification often present
2 types of atypical hyperplasia of breast
Atypical ductal hyperplasia — relatively monomorphic proliferation of regularly spaced cells; distinguished from DCIS in that it only partially fills involved ducts
Atypical lobular hyperplasia — cells identical to those of LCIS but cells do not fill or distend more than 50% of acini within a lobule; associated with loss of e-cadherin expression
Features of DCIS
Malignant clonal proliferation of epithelial cells limited to ducts and lobules by the basement membrane
Rarely palpable, almost always detectd by mammography
Comedo type has clustered or linear branching areas of calcification; defined by tumor cells with pleomorphic high-grade nuclei and areas of central necrosis
Non comedo type lacks either high grade nuclei or central necrosis, but overall pattern varies
Features of LCIS
Clonal proliferation of cells within ducts and lobules that grow in discohesive fashion d/t acquired loss of E-cadherin (CDH1); almost always expresses ER and PR (not HER2)
Always incidental finding, bc there is no associated calcification or stromal rxn
Uniform population of cells with oval or round nuclei with small nucleoli involving ducts and lobules; mucin-positive signet ring cells often present
Pathogenesis and clinical significance of paget disease of the nipple
Occurs when malignant (paget) cells from DCIS migrate within ductal system via lactiferous sinuses into nipple skin without crossing basement membrane
Palpable mass is present in 50-60% of cases, and almost all have underlying invasive carcinoma — usually poorly differentiated, ER-negative, and overexpress HER2. Those without palpable mass likely have DCIS
Which of the following is most common in breast cancer?
A. ER+, HER2-
B. ER+, HER2+
C. ER-, HER2+
D. ER-, HER2-
A. ER+, HER2-
Features of BRCA1 mutations
Associated with 52% of all breast cancers; pts have 40-90% risk of any cancer dx by age 70
Associated with increased risk of familial breast, ovarian, prostate, pancreas, and fallopian tube cancer
Breast carcinomas are commonly poorly differentiated and triple negative (basal-like) and have TP53 mutations
Features of BRCA2 mutations
Associated with 32% of all breast cancers, 30-90% overall risk of cancer by age 70
Associated with increased risk of familial breast, ovarian, male breast, prostate, pancreas, stomach, melanoma, gallbladder, bile duct, and pharyngeal cancer
Biallelic germline mutations cause rare form of fanconi anemia
Features of TP53 mutations
Li fraumeni syndrome
Associated with familial breast cancer, sarcoma, leukemia, brain tumors, adrenocortical carcinoma, and others
Most commonly mutated gene in sporadic breast cancer, 53% ER+, HER2+
Features of CHEK2 mutation
Associated with familial breast cancer, prostate, thyroid, kidney, and colon cancer
May increase risk for breast cancer after radiation exposure, 70-80% ER+
