Pathoma CH. 16 Breast Pathology Flashcards
Where are breast derived from embryologically?
From the skin—modified sweat glands
What is the functional unit of the breast?
Terminal duct lobular unit
What are the two epithelia lining the lobules and ducts of the breast?
Luminal cell layer
Myoepithelial cell layer
What is the liminal cell layer of the breast responsible for?
Milk production
What is myoepithelial cell layer of the breast responsible for?
Propels milk toward nipple
What occurs during pregnancy to the breast lobules and what drives this?
Hyperplasia—driven by estrogen and progesterone produced by the corpus luteum, fetus and placenta
What occurs to breast tissue after menopause?
Atrophy
Milk production outside of lactation…
Galactorrhea
Name 3 causes of galactorrhea…
Nipple stimulation
Prolactinoma of the anterior pituitary
Drug side effect
Bacterial infection of the breast caused by staphylococcus aureus and is associated with breastfeeding…
Acute mastitis
A breast feeding mother presents with erythematous breasts with purulent discharge from the nipple. Cultures are taken and staphylococcus aureus is found to be causing the infection. What is the most likely diagnosis?
Acute mastitis
What is the treatment for acute mastitis?
Continued drainage and antibiotics→ dicloxacillin
A 35 year old female patient presents with a subareolar mass and nipple retraction. She has a 15 year history of smoking and is found to have vitamin A deficiency. What is the most likely diagnosis for this patient?
Periductal mastitis→ inflammation of the subareolar ducts
Vit A deficiency→ squamous metaplasia of lactiferous ducts—blocking ducts causing inflammation
A postmenopausal women presents with a periareolar mass, green-brown nipple discharge and biopsy shows chronic inflammation with plasma cells. What abnormality is this patient most likely presenting with?
Mammary duct ectasia→ inflammation with dilation (ectasia) of the subareolar duct
30 y/o female patient presents with palpable mass upon breast examination. Abnormal calcification in seen on mammography and the biopsy shows calcifications and giant cells. What is the most likely diagnosis?
Fat necrosis→ most likely due to trauma—patient doesn’t always report trauma. Necrotic fat is also seen on biopsy
What is the most common abnormality occurring to the breast seen in premenopausal women?
Fibrocystic change—development of fibrosis and cysts
What is the presentation for fibrocystic change of the breast both on physical exam and gross exam?
PE—irregularity of the breast tissue in upper outer quadrant (lumpy breast)
Gross exam—Blue-dome appearance
What are the 3 different types of fibrocystic change that happen to the breast and their relative risk of developing invasive carcinoma?
1) Fibrosis, cysts, and aprocrine metaplasia→ NO risk
2) Ductal hyperplasia and sclerosing adenosis→ 2x increased risk
3) Atypical hyperplasia→ 5x increased risk
A 30 y/o women presents with bloody nipple discharge. Upon biopsy, fibrovascular projections lined by epithelial and myoepithelial cells are found. What is the most likely diagnosis for this patient and what does this diagnosis need to be differentiated from?
Intraductal Papilloma→ must be differentiated from papillary carcinoma because that too presents as bloody discharge.
How is intraductal papilloma distinguished from papillary carcinoma?
They both present as bloody discharge from the nipple and have fibrovascular projections lined by epithelial cells→ however, Intraductal papilloma presents with underlying myoepithelial cells—whereas carcinoma does NOT—also presents most commonly in premenopausal women and carcinoma increases with age—therefore is most commonly seen in postmenopausal women.
What is the most common premenopausal benign neoplasm of the breast?
Fibroadenoma
35 y/o female patient presents with well-circumscribed, mobile marble-like mass which becomes painful during her menstrual cycle. What is the most likely diagnosis for this patient?
Fibroadenoma
Why does a fibroadenoma increase in size during pregnancy and cause pain during the menstrual cycle?
Fibroadenomas are estrogen sensitive and therefore will respond to estrogen changes during menstruation and pregnancy
Does having a fibroadenoma increase a woman’s chance of developing a breast carcinoma?
No
A postmenopausal woman presents with a fibroadenoma-like tumor with overgrowth of the fibrous part of the tumor. Upon biopsy leaf-like projections are seen. What is the most likely diagnosis for this patient?
Phyllodes tumor
Name the 6 risk factors involved in breast cancer…
1) Female gender
2) Age→ usually arises in postmenopausal women
3) Early menarche/late menopause
4) Obesity
5) Atypical hyperplasia
6) First degree relative—mother/sister/daughter
Risk factors are related to estrogen exposure.
Malignant proliferation of cells in breast ducts with no invasion of the basement membrane…
Ductal carcinoma in situ (DCIS)
What is seen on mammography that could indicate ductal carcinoma in situ (DCIS)? What other diseases are associated with this finding?
Calcification
Benign conditions→ fibrocystic changes (sclerosing adenosis) and fat necrosis
Biopsy is necessary to distinguish between benign and malignant conditions
What classifies the comedo type of ductal carcinoma in situ?
High-grade cells with necrosis and dystrophic calcification in the center of the duct
Patient presents with erythematous nipple with ulceration. It was discovered that there was underlying carcinoma and further work-up was needed. What disease is most associated with these symptoms?
Paget disease of the breast→ DCIS extending up the duct involving the skin of the nipple
Almost always involves underlying carcinoma
Patient presents to clinic because of a palpable mass found during self examination of the left breast. Mammography is performed and a 2.2 cm mass if found in the left breast. Biopsy shows duct-like structures in a desmoplastic stroma. What is the most likely diagnosis for this patient?
Invasive ductal carcinoma
PE→ usually 2cm or more
Mammography→ 1cm or more
Advanced→ dimpling of the skin/retraction of the nipple
What are the four special subtypes of invasive ductal carcinoma of the breast?
Tubular carcinoma
Mucinous carcinoma
Medullary carcinoma
Inflammatory carcinoma
What subtype of invasive ductal carcinoma of the breast is defined by well-differentiated tubules lacking myoepithelial cells and has a good prognosis?
Tubular carcinoma
What subtype of invasive ductal carcinoma of the breast is defined by carcinoma with abundant extracellular mucin, occurs in older women, and has a good prognosis?
Mucinous carcinoma
What subtype of invasive ductal carcinoma of the breast is defined by large, high-grade cells growing in sheets with associated lymphocytes and plasma cells, can mimic fibroadenoma on mammography, has a good prognosis, and has increased incidence in BRCA1 patients?
Medullary carcinoma
What subtype of invasive ductal carcinoma of the breast is defined by carcinoma in dermal lymphatics, inflamed, swollen breast are seen on physical exam, can be mistaken for acute mastitis, and has a poor prognosis?
Inflammatory carcinoma
What is lobular carcinoma in situ (LCIS)?
Malignant proliferation of cells in the breast lobules→ no invasion of the basement membrane
How is lobular carcinoma in situ often found and why is it such a difficult disease to detect?
Usually found incidentally on biopsy
No mass or calcifications are formed—therefore making it difficult to discover
What protein is missing in lobular carcinoma in situ (LCIS)?
E-cadherin—cells are found dyscohesive on biopsy
What is the treatment and prognosis of Lobular carcinoma in situ (LCIS)?
Tamoxifen is used for treatment—anti-estrogen on the breast, however pro-estrogen on the uterus
Low risk of progression to invasive carcinoma
What type of breast carcinoma is seen growing in a single-file line of cells and no duct formation is seen due to lack of E-cadherin?
Invasive lobular carcinoma
What is the most important factor for prognosis of breast cancer?
Metastasis→ however, most patient present before metastasis
What is the most useful prognostic factor used for breast cancer?
Spread to axillary lymph nodes
What procedure is used to assess the axillary lymph nodes?
Sentinel lymph node biopsy
What are the most important predictive factors for the response to treatment of breast cancers?
Estrogen Receptor (ER) status Progesterone receptor (PR) status HER2/neu gene amplification status
If a patient is both estrogen and progesterone receptor positive, what treatment will elicit the best response?
Antiestrogenic agents—Tamoxifen
Both of these receptors are located within the nucleus
A patient is found to be positive for HER2/neu gene amplification. What is the most appropriate therapy for this patient?
Trastuzumab (Herceptin)→ antibody directed against the HER2 receptor
What type of prognosis is seen in patients who are found to have a triple negative breast carcinoma tumor—ER +, PR + and HER2/neu +? Who is at an increased risk of developing a triple negative tumor?
Poor prognosis
African American women are at an increased risk of developing a triple negative carcinoma
What a some clinical features suggestive of a hereditary breast cancer?
Multiple first degree relatives with breast cancer
Premenopausal breast cancer
Multiple tumors in a single patient
What is the BRCA1 mutation associated with?
Breast and ovarian carcinoma
What is the BRCA2 mutation associated with?
Breast carcinoma in males
What is the most common presentation for males who have developed breast cancer?
Subareolar mass and possible nipple discharge
What is the most common histological subtype of breast cancer seen in males?
Invasive ductal carcinoma
What syndrome is associated with male breast cancer?
Klinefelter syndrome
