4. Breast Flashcards
Nipple (normal) (7)
Circular smooth muscle overlying 4th intercostal space.
Typically 5-10 ductal openings.
Inversion: nipple invaginates into the breast.
Retraction: nipple pulled back slightly.
Can both be normal if chronic, if acute, think underlying cancer.
Areola will darken with puberty and parity.
Nipple enhancement on MRI is normal.
Cooper ligaments (3)
Thin sheets of fascia holding the breasts up.
Tiny white lines on mammography, echogenic lines on US.
Straightening and tethering manifests as architectural distortion, occurs in surgical scars, radial scars and IDC.
Fibroglandular tissue (5)
Breast mound is fibrous tissue with fat, ducts and glands laying on top of anterior chest wall.
Axillary extension is called “tail of spence”.
Upper outer quadrant is more densely populated with breast tissue, hence more cancers start there.
No dense tissue usually in medial/inferior breast and retroglandular regions.
These are considered danger zones, where cancer can hide.
Breast asymmetry (3)
Common and usually normal, as long as no other findings.
Can be a sign of “Shrinking breast” in invasive lobular breast cancer.
Think cancer if size difference is new or parenchyma looks asymmetrically dense.
Lobules (3)
Flower shaped milk producing areas. Terminal duct and lobule are referred to as a “terminal duct lobule unit” or TDLU.
Most breast cancers start here.
Ducts (3)
Ductal system branches like roots or branches of a tree.
Branches overlap wide areas and not clearly segmented.
Calcifications that appear to follow the duct “linear or segmental” are most sus for cancer.
Lactiferous sinus (3)
Milk from lobules drains into major duct under the nipple.
The dilated portion of the major duct is sometimes called Lactiferous Sinus.
It’s normal and not a mass.
Blood supply/lymphatic drainage (3)
60% blood supply by internal mammary.
Rest is via lateral thoracic and intercostal perforators.
97% lymph drainage is to axilla, 3% to internal mammary nodes.
Axillary lymph node levels (4)
Level 1: Lateral to pec minor
Level 2: under pec minor
Level 3: Medial to pec minor
Rotter node: Between pec major and minor
Mets to internal mammary nodes (3)
If you can see the nodes on US, they’re abnormal.
Isolated mets to these nodes is uncommon, and if seen it’s usually from a medial cancer
Sternalis muscle (3)
Non functional muscle next to sternum, can simulate a mass.
ONLY seen in CC view.
Usually unilateral.
Will be seen on previous imaging.
Breast development/physiology (6)
“Milk streak” is the embryological buzzword to explain location of normal breast and location of ectopic breast tissue.
Most common location for ectopic breast tissue is the axilla (then inframammary fold).
Extra nipples are most commonly in the same locations, but can be anywhere along the “milk streak”.
Males and females can have breast enlargement at birth and produce milk (maternal hormones).
As girls enter puberty, ducts elongate and branch (due to oestrogen), then their lobules proliferate (progesterone).
Biopsying a breast bud can damage it and affect breast development.
Follicular phase (breast) (3)
Day 7-14.
Oestrogen dominates.
Best time for mammogram and MRI.
Luteal phase (breast) (4)
Day 15-30.
Progresterone dominates.
Some breast tenderness (max day 28-30).
Breast density increases slightly.
Pregnancy (breast) (3)
Tubes and ducts proliferate.
Breast gets a lot denser (more hypoechoic on US).
US may be best bet if suspecting mass.
Perimenipausal breast (3)
Shortening of follicular phase means breast gets more progesterone exposure, which means more breast pain, more fibrocystic change and more cyst formation.
Menopausal (breast) (4)
Lobules decrease.
Ducts stay but become more ectatic.
Fibroadenomas degenerate (they like oestrogen) and get their popcorn calcifications.
Secretory calcifications will develop, but not for 15-20 years post menopause.
Hormone replacement therapy (breast) (2)
Breast can get more dense (even more oestrogen-progesterone combos).
Breast pain can occur, peaking usually in first year.
Fibroadenomas can grow.
Lactation (4)
Breast gets a lot denser in third trimester. Mammogram is more difficult and US becomes more useful.
Pituitary prolactinoma or meds (classically antipsychotics) can create similar bilateral increased density.
Biopsying a breast at this time risks creating a milk fistula. Need to stop breastfeeding to stop the fistula. The fistula can (rarely) get infected.
Galactocele (3)
Benign fat containing lesion, typically seen on cessation of lactation.
Location is usually subareolar.
Appearance is varied, but can have classic fat-fluid level.
Lactating adenoma (3)
Look like fibroadenomas, usually multiple.
Follow up 4-6 months post partum, post delivery or after cessation of lactation (ultrasound).
Rapidly regress after you stop lactation.
Mammogram - technique (7)
2 standard views, craniocaudal (CC) and Medial Lateral Oblique (MLO)
Posterior Nipple Line is drawn on MLO, from nipple to chest wall. Needs to touch pec muscle to be adequate.
On CC, draw line from nipple back to chest wall. Should be within 1cm of length of posterior nipple line.
Ideally inframammary fold should be visualised.
“Camel nose” buzzword used to describe a breast on MLO that has not been pulled up and out by radiographer.
Nipple should be in profile in one of 2 views to avoid missing subareolar cancer.
Relaxed pec muscles preferred (concave instead of convex), showing more breast tissue.
LMO view (3)
MLO view is standard, sometimes LMO view is used:
- Women with kyphosis or pectus excavatum.
- to avoid medial pacemaker or central line.
MLO view trivia (1)
MLO contains most breast tissue of any view
Spot compression views (2)
usually need to leave the collumnator open, to give the largest field of view.
Small paddles give better focal compression, large paddles allow good visualisation of land marks.
Magnification views (2)
CC and ML (true lateral are obtained). ML (as opposed to MLO) used to help catch “milk of calcium”
ML vs LM for true lateral view (4)
True lateral is useful for localising things seen on single view only (CC).
If a mass is lateral on CC (screening mammo) then use ML for diagnostic. If medial, use LM.
This is to move the mass closer to the detector.
If mass only visible on MLO, use ML, as 70% of breast cancers occur laterally.
Blur artefact (4)
Blur:
- Can be breathing or inadequate compression, typically inferior breast on MLO.
- Can be tricky to pick up.
- Look at cooper ligaments, they should be thin white lines in fat. If thick or fuzzy, this is likely blur (or oedema)
- If skin thickening, think oedema
Grid lines (4)
Mammograms should always use a grid, unless mag view.
Grid works by moving really fast and keeping only X rays that move in straight line.
Blur is seen in 3 scenarios
- Patient moved.
- Exposure too long
- Exposure too short
Screening mammograms - general tips (6)
Trying to find 3-8 cancers per 1000 mammograms.
Certain areas can only be seen on a single view, e.g. medial breast on CC may not be seen on MLO.
Inferior posterior breast may not be seen on CC.
Makes these areas high risk for missing cancer.
Recommended to look at mammograms from 2 years prior for comparison, makes it easier to see early changes.
Localising lesion (3)
Medial lesion on CC film will be more superior on MLO, and even more superior on ML.
Opposite is true of lateral lesions.
Lead Sinks and Muffins Rise (from CC to MLO to ML)
Localising lesion (only seen in CC) (4)
Rolled CC view can help determine if lesion is in superior or inferior breast.
Position breast for CC view, but prior to compression, the breast is rotated medially or laterally along axis of nipple.
Reference point is top of breast.
If you roll the breast medially, superior tumour will move medial and inferior tumour will move lateral.
Opposite is true of you roll breast laterally.
BI-RADS/UK System (3)
BI-RADS developed by Americal College of Radiology.
UK uses a 5 point breast imaging scoring system for communication and diagnosis.
M1-5 and U1-5 for mammograms and ultrasound respectively.
Calcifications (4)
Earliest sign of breast cancer.
3 types
- Artefact
- Benign
- Suspicious
Artefact calcifications (3)
Deoderant
- high density material seen in axilla
- High density speck that doesn’t change position with different views (implies it’s on the receptor)
Zinc oxide
- Ointment for breasts, can collect on moles and mimic calcifications.
- Disappears on follow up
Metallic artefact
- Electrocautery devices can leave small metal fragments in the breast.
- Will be very dense and adjacent to a scar
Benign vs suspicious (3)
Based on morphology and distribution.
Most cancers start in ducts, so linear or segmental calcification is most concernng.
Bilateral scattered calcifications are least concerning.
Dermal calcifications (4)
Benign, found anywhere women sweat (folds, cleavage, axilla).
Often grouped like paw of a bear, or foot of a baby.
They stay in same place on CC and MLO views (tattoo sign).
Tangential view to confirm they’re dermal.
Vascular calcifications
Parallel linear calcifications, usually obviously vascular.
Popcorn calcifications (2)
Immediate buzzord for degenerating fibroadenomas.
Usually begin around the periphery and slowly coalesce over subsequent images.
Secretory, rod like calcifications (5)
Big, easily seen and point to the nipple.
Usually bilateral
“Cigar chaped with lucent center”
“Dashes but no dots”
10-20 years after menopause, happen after duct has involuted.
Eggshell calcifications (4)
Due to fat necrosis.
Can be from any trauma (surgical or accident).
If very big, can be called “liponecrosis macrocystica”.
Lucent centered is a buzzword.
Dystrophic calcifications (3)
Seen after radiation, trauma or surgery.
Usually big.
“Irregular in shape”, can also have lucent centre.
Milk of calcium (4)
Very characteristic look.
On CC, calcifications look powdery and spread out, on MLO they may layer.
on ML, they layer into a more linear appearance, with a curved bottom “tea cupped”.
Due to fibrocystic change, it’s fluid-fluid in a lobule.
No calcification on biopsy? (2)
Milk of calcium needs to be viewed with polarised light to assess birefringence.
Otherwise calcifications can’t be seen.
Round calcifications (4)
Develop in lobules, usually scattered, bilateral and benign.
Usually due to fibrocystic change when benign.
If bilateral, multiple and similar, they’re benign.
If solitary or different, it’s suspcious. (like a mass).
Amorphous calcifications (8)
Suspicious.
Look like powdered sugar, should not be able to count each one.
Scattered and bilateral suggest benign, segmental is concerning.
DDx
- Fibrocystic change (most likely)
- Sclerosing adenitis
- Columnar cell change
- DCIS (low grade)
Coarse heterogenous calcifications (9)
Suspicious.
Countable, but their tips are dull.
Usually bigger than 0.5mm.
Distribution and comparison to priors is important.
Can be associated with mass (fibroadenoma or papilloma)
DDx
- Fibroadenoma
- Papilloma
- Fibrocystic change
- DCIS (low to intermediate grade)
Fine pleomorphic calcifications (6)
Countable and sharp, usually smaller than 0.5mm.
Highest suspicion for malignancy
DDx
- Fibroadenoma (less likely)
- Papilloma (less likely)
- Fibrocystic change
- DCIS (high grade)
Fine linear/fine linear branching calcifications (2)
This distribution makes fine pleomorphic calcifications look even more suspicious.
DDx narrows to basically DCIS or atypical look for secretory or vascular calcifications.
Calcifications associated with focal asymmetry/mass (3)
Increased density around suspicious calcifications increases risk of cancer.
Sometimes called “puff of smoke” sign or a “warning shot”.
US is useful for extent of disease.
Calcifications in/near lumpectomy scar (2)
Local recurrence rate is around 6%.
New calcifications with suspicious morphology (not fat necrosis) should be biopsied.
When to US calcifications (3)
US not usually used to evaluate pure calcification finding.
Exceptions are
- If patient had mass associated with calcifications
- if patient had palpable finding
Mondor disease (4)
Thrombosed vein presenting as tender palpable cord.
Looks like thrombosed vessel on US.
Not a DVT, doesn’t need anticoag.
Rx: NSAIDs and warm compress.
Fat containing lesions (5)
5 classic causes, all are benign.
- Hamartoma
- Galactocele
- Lymph node
- Lipoma
- Oil cyst/fat necrosis
Only last 2 are consudered pure fat containing lesions
Hamartoma (2)
“breast within a breast”. Difficult to see on US as they blend into breast tissue
Galactocele (2)
Young lactating women, usually on cessation of lactation.
Usually subareolar, varied appearance, but can have fat-fluid level.
Oil cyst/fat necrosis (4)
Areas of fat necrosis walled off by fibrous tissue.
Seen randomly, post trauma or post surgery.
Peripheral calcifications pattern is usually egg shell.
Lots of them may suggest Steatocystoma Multiplex.
Lipoma (2)
Usually radiolucent with no calcifications.
Enlargement of a lipoma is a criteria for biopsy.
Intramammary lymph node (2)
Normal, typically located in tissue along pectoral muscle, often close to vessels.
NOT seen in fibroglandular tissue.
When to US (3)
Usually palpable finding will get US, and under 30s will mostly skip mammography.
One exception is a fat containing lesion is a definate benign finding on diagnostic mammography
Pseudoaneurysmal Stromal Hyperplasia (PASH) (4)
Benign myofibroblastic hyperplastic process.
Usually a big (4-6cm) solid, oval shaped lesion with well defined borders.
Can be seen between 18-50 years old.
Usually recommend annual follow up.
Fibroadenoma (4)
Commonest palpable mass in young women.
Usually oval, circumscribed mass with homogenous, hyopechoic echotexture and central hyperechoic band.
If shown in an older patient, more likely to have course, popcorn calcifications.
MRI: T2 bright with type 1 enhancement (progressive)
Phylloides (5)
10% risk of malignant degeneration.
Can metastasize, usually haematogenous to the lungs and bone.
Fast growing breast mass.
Need wide margins on resection, higher recurrence if margin <2cm.
Occurs in older age than fibroadenomas (40s-50s).
Biopsy of sentinel node is not needed, as mets to lymphatics are rare.
Distinguishing features of Phylodes tumour (4)
Rapid growth.
Haematogenous mets
Middle age to older women
Mimics a fibroadenoma