Breast disease Flashcards
Describe the anatomy of the breast
What is the functional unit?
“modified sweat gland”
- 15-20 lobes, each acting as an independent glandular unit with a lactiferous duct opening to the nipple
- Functional unit is the “terminal duct lobular unit” (TDLU)
- TDLU (multiple will all empty into a lactiferous duct) -> intralobular ducts -> interlobular ducts -> lactiferous duct, these turn into lactiferous sinuses towards the nipple
- Interlobular stroma is present between lobes and divides each lobe into numerous lobules
- Intralobular stroma surrounds each TDLU
Describe the histology of the breast tissue
What are the linings of this tissue?
- Lining of major ducts ranges from double-layered cuboidal epithelium in the smaller ducts (those closest to TDLU)
-> to pseudostratified columnar
-> to stratified squamous epithelium in largest ducts (those nearest the nipple) - Myoepithelial layer beneath lining epithelium, overlying basement membrane
- Inner epithelium layer is what is usually affected by cancer malignant change - if still surrounded by the myoepithelial layer, this means in situ, if it is no longer surrounded by myoepithelial and basement membrane then it is considered invasive.
What are the clinical presentations of breast disorders?
- Palpable mass
- “Lumpiness” (w/o discrete mass)
- Pain
- Nipple discharge
- Mammographic abnormality
How do you sample breast disorders?
- Nipple discharge
- Fine needle aspiration biopsy
- Core biopsy* - most common way (core needle -
The removal of a tissue sample with a wide needle for examination under a microscope.) - Punch biopsy (A procedure in which a small round piece of tissue about the size of a pencil eraser is removed using a sharp, hollow, circular instrument.)
- Breast duct excision
- lumpectomy/ partial mastectomy
- Mastectomy
Describe fat necrosis
Benign breast disorder
Breast fat necrosis is a non-suppurative inflammation of adipose tissue caused by the disruption of oxygen supply to fat cells, ultimately leading to cell death.
Firm, irregular mass; +/- erythema of overlying skin, skin retraction and dimpling - from interlobular stroma
- May be history of trauma
- Often superficial
- Can closely mimic cancer (all symptoms listed set off alarm bells for cancer) - clinically concerning
- Necrotic adipose tissue surrounded by inflammatory cells
Describe acute mastitis
Where/ when? etiology? signs+symptoms? differential diagnosis? complications?
Benign breast disorder
Acute mastitis is usually a bacterial infection and is seen most commonly in the postpartum period. Bacteria invade the breast through the small erosions in the nipple of a lactating woman, and an abscess can result.
- From large, lactiferous ducts
- Most cases occur during lactation/ breastfeeding/ chestfeeding (breast milk can lead to infection)
- Predisposing factors: cutaneous fissures in nipples and breast engorgement
- Etiologic agents: Staphylococci & Streptococci
- Signs and symptoms: breast is tense, hot, painful; axillary lymphadenopathy; general signs and symptoms of acute infection
- Differential diagnosis: inflammatory carcinoma
- Complications: abscess formation requiring surgical drainage; healing of area by fibrosis may result in fixation of overlying skin mimicking carcinoma (healing by fibrosis -> may cause fixation which mimics cancer)
Describe intraductal papilloma
Where? Age? Appearance?
Benign breast disorder/ lesion
Intraductal papilloma is a small, noncancerous (benign) tumor that grows in a milk duct of the breast.
- From nipple, large lactiferous
- 30s-50s
- Bloody nipple discharge or palpable areolar mass (more rarely)
- Tan-pink friable lesion within a dilated duct
Treatment -> local excision
Describe fibroadenoma
where? age? features? appearance?
- From the intralobular stroma
- Most common cause of a benign breast mass
- May occur at any age, but are most common in female patients between 20 and 35 years
- Features: discrete, mobile, usually non-tender breast mass
- Rounded/ lobulated contours
- Firm to rubbery texture, may calcify
- No dimpling/ retraction of overlying skin
- Composed of both stromal and epithelial elements
- No atypia, rare stromal mitoses
- More aggressive counterpart of fibroadenoma: phyllodes tumour
Describe Non-proliferative/ fibrocystic change
- From the TDLU (terminal duct lobular unit)
- Clinically, this term has been applied to a condition in which there are palpable breast masses that fluctuate with the menstrual cycle and may be associated with pain and tenderness.
- However, at least 50% of female patients have palpably irregular breasts and, in many, these palpable lumps probably represent physiological changes rather than a pathologic process. Thus, the term “fibrocystic change” is a more appropriate term to use. The removal of the word disease also removes the implication that all of the changes encompassed by this term are associated with an increased risk of subsequent carcinoma development.
- The vast majority of patients designated as having fibrocystic change are not at any increased risk for developing breast cancer. Several studies have shown that by separating the various histologic components of fibrocystic change, subgroups of patients with different risks for breast carcinoma development may be identified.
- Cysts (lots of cystic spaces), fibrosis, apocrine metaplasia, mild “usual” epithelial hyperplasia
- Often not treated with excision
What is the system for classifying benign breast lesions into relative risk categories? what are the 3 categories?
- Non-proliferative lesions aka fibrocystic change (no increased risk for subsequent breast cancer - relative risk, RR, of malignancy is x1)
- Proliferative lesions without atypia (mildly increased risk for subsequent breast cancer: RR x 1.5-2)
- Proliferative lesions with atypia aka atypical hyperplasias (moderately increased risk for subsequent breast cancer: RR X 4-5, FamHx, familial history + AH: RR x9-10) - cannot be ignored, clinical follow-up and/or excision
Name some of the benign breast disorders that fall under the category Non-proliferative lesions aka fibrocystic change
- Cysts
- Apocrine change
- Duct ectasia (Mammary duct ectasia occurs when one or more milk ducts beneath your nipple widens. The duct walls may thicken, and the duct may fill with fluid. The milk duct may become blocked or clogged with a thick, sticky substance.)
- Fibrosis
- Mild hyperplasia
Name some of the benign breast disorders that fall under the category Proliferative lesions without atypia
Florid/ moderate epithelial hyperplasia
Intraductal papillomas
Sclerosing adenosis
Complex sclerosing lesion/ radial scar
Complex fibroadenoma
Name some of the benign breast disorders that fall under the category Proliferative lesions with atypia aka atypical hyperplasias
Atypical ductal hyperplasia
Atypical lobular hyperplasia
Where does breast cancer tend to be located
Tends to be from the TDLU part of the breast
terminal duct lobular unit
What are the risk factors of breast cancer?
- Gender: W>M (lifetime risk of breast cancer is approximately 1 in 8 for females living in North America - highest risk for cancer in women, 2nd leading cause of cancer death
- Age and sex: 75% occur in 50+ age group
- Family history: 80% sporadic, 20% family history
- Geographic factors: americas/ europe > asia/ africa
- Race/ ethnicity: genetic, social determinants of health
-> Black women have a lower lifetime risk in comparison to white women of european descent. Have a lower risk of the triple negative hormones of the cancer, which is more aggressive. - Reproductive history: early menarche (first period), nulliparity (never having been pregnant), not breastfeeding, older age at 1st pregnancy
- Ionizing radiation: especially if exposure occurs while breast still developing (e.g. rads for HL in young women)
- Others: obesity, hormone replacement, mammographic density (dense breast tissue), EtOH
