Pathoma Breast Pathology Flashcards
What is galactorrhea and some causes?
Galactorrhea - Milk production outside lactation (i.e. breastfeeding/lactorrhea). Common causes include drug-induced (i.e. neuroleptic drugs, cimetidine, birth control pills), prolactinoma, or nipple stimulation (i.e. a woman adopts a child and wants to breastfeed it can happen)
NOT breast cancer
What is periductal mastitis, what is the pathogenesis, and who tends to get it?
Painful subareolar mass which occurs as keratinizing squamous metaplasia occurs in the ducts, which causes duct blockage and inflammation. There will be a granulomatous response to spilled keratin, and chronic inflammatory infiltrate.
Occurs in smokers -> have a relative vitamin A deficiency, causing squamous metaplasia
What can periductal mastitis be confused for?
Can be confused for breast cancer -> subareolar mass, and nipple is often retracted
What is mammary duct ectasia and what inflammatory infiltrate is seen?
Inflammation with dilation (ectasia) of subareolar ducts
-> chronic inflammatory infiltrate with plasma cells and lipid-laden macrophages is seen on biopsy
What is the classical presentation of mammary duct ectasia and what can it be confused with?
Presents as periareolar mass with “green-brown” nipple discharge due to inflammatory debris.
-> try to remember it as being dilated full of “green-brown nipple discharge”
Happens in post-menopausal women, so easily confused with breast cancer.
What benign entity is most likely to mimic breast cancer both clinically and on mammography? What is its pathogenesis?
Fat necrosis
- > trauma leads to formation of a hard mass which is necrotic
- > dystrophic calcification (due to saponification) allows it to be seen on mammography
What will patients present with clinically in fat necrosis and what will biopsy show? Treatment?
Present clinically with a benign lump, often with skin retraction. Patients often remember no traumatic event.
Biopsy shows necrotic fat cells and giant cells (inflammatory infiltrate lining fat cells)
What is the single most common change in the premenopausal breast and what is the cause? What age group is susceptible?
Fibrocystic changes -> older premenopausal women (>35 years).
Thought to be due to abnormal hormonal response / sensitivity
What is the typical presentation of fibrocystic changes? How does it usually occur, and is it a benign entity?
Breast pain, swelling, and tenderness which is associated with areas of nodularity, induration, and gross cysts
- > vague irregularity of breast tissue, especially upper outer quadrant
- > often bilateral (equal on both sides)
Fibro = Areas of fibrosis between expanded cysts Cystic = Lobular units become cystic and dilated, often with bleeding into them due to erosion of nearby blood vessels - "blue dome cysts"
Inherently a benign entity but some changes which can occur related to this condition increase your risk for invasive breast cancer.
What is the common fibrocystic-related change which is notably NOT associated with increased risk of cancer?
Apocrine metaplasia - eosinophilic blebbing at epithelial surface
Will arise in conjunction with the common benign changes of fibrosis and cystic blue dome dilations
What two lesions are associated with roughly 2x risk of breast cancer as fibrocystic changes? How will the lumens look on the ductal one?
- Usual ductal hyperplasia - excess benign cells lining ducts-> lumens will appear irregular (indicates benign), a type of proliferative change
- Sclerosing adenosis - adenosis = glands, sclerosing = fibroblasts, this is a normal looking hyperplasia of acini with intermixed fibrosis. Often becomes calcified (confusable on mammogram)
What fibrocystic lesions are at greater risk (5x) of progressing to breast cancer? How will the lumens of the ductal one appear?
- Atypical ductal hyperplasia - lumens within the proliferated ducts appear more round than usual ductal hyperplasia, and cells are monomorphic / atypical
- Lobular hyperplasia - increased number of cells lining each lobule, look like “marbles in a petri dish” acini
Which breast is affected with an increased cancer risk due to fibrocystic changes?
Both breasts are -> much like LCIS, fibrocystic changes can be treated as a risk factor for the development of breast cancer in either breast.
What is the most common cause of serous or blood nipple discharge? How can you tell if it’s benign or malignant? What age is the typical presentation?
Intraductal papilloma
-> papillary growth into a large duct, typically under the areola.
Can see two layers of cells (luminal layer, myoepithelial layer) to know it’s not malignant (malignant = loss of myoepithelial layer).
Typically presents in a PREmenopausal female -> another way to differentiate it from papillary carcinoma
What is the most common benign neoplasm of the breast, and who tends to get it?
Fibroadenoma, usually in premenopausal women <35
What is the growth pattern of fibroadenoma and does it increase your risk for cancer?
Small, well-circumscribed mass, usually solitary. Includes fibrous component (fibro-) with proliferative connective tissue, and a gland component (-adenoma).
It is estrogen-sensitive, so it grows during pregnancy and prior to menstruation.
No increased risk of cancer.
What neoplasm should be suspected if what was presumed to be a fibroadenoma does not regress after menopause? What is its growth pattern?
Phyllodes tumor
- > fibroadenoma-like (both proliferations of glands and stroma) but has an overgrowth of the “fibrous” mesenchymal component of the tumor
- > They have a very cellular stroma -> sarcomatous type tumor (stroma can be very ugly, much less benign looking than fibroadenoma).
- > characteristic “leaf-life” projections of fibrous tissue on biopsy
What is the pattern of spread of phyllodes tumor and what must be done to deal with them? How do they spread if they become malignant?
Usually benign, and must be resected with wide margins (like pleomorphic adenoma) to prevent recurrence.
If they become malignant (rare) they will spread by blood rather than lymph nodes due to being a sarcoma.
What is Paget disease and what will it look like on the patient? Is this DCIS or invasive cancer?
Extension of neoplastic adenocarcinoma cells through the ducts to involve the skin of the nipple (intraepithelial adenocarcinoma cells)
Appears as ulceration and erythema of the nipple
It can be either DCIS or invasive adenocarcinoma
How will Paget disease appear histologically? How should you manage it?
Similar to extramammary Paget disease
-> “Paget cells” clear cytoplasm in the epidermis, either singly or in clusters.
Patient generally needs biopsy with removal of the lump since it’s almost always associated with underlying carcinoma when in the breast
What is the most common type of breast cancer? How does it present classically on the outside and with a mammogram?
Invasive ductal carcinoma.
Presents as a firm, fibrous, rock-hard mass with dimpling of the skin or retraction of the nipple due to desmoplasia.
Often has a characteristic stellate shape on mammogram with little tentacles reaching out -> ductal proliferations going everywhere.
What are the four main subtypes of invasive ductal carcinoma?
- Tubular carcinoma
- Mucinous carcinoma
- Medullary carcinoma
- Inflammatory carcinoma
What is the most classic subtype of invasive ductal carcinoma? Prognosis?
Tubular carcinoma - well-differentiated tubules that lack myoepithelial cells (malignant), surrounded by desmoplastic stroma -> good prognosis
What is mucinous carcinoma? Prognosis?
Invasive ductal carcinoma characterized by abundant extracellular mucin
“Cells are stuck in mucus so they can’t go anywhere” - good prognosis -> rarely metastasizes
