Mammo Anatomy

Question 1

Nipple

Answer 1

Smooth muscle, 4th IC space, 5-10 ductal openings

InVersion: InVaginates into breast

Retraction: pulled back slightly

Both can be NORMAL IF CHRONIC
IF NEW –> distortion from cancer

Areola darkens with puberty and pregnancy

Nipple enhancement on contrast breast MRI is NORMAL- DONT CALL IT PAGETS.

Question 2

Fibroglandular tissue

Answer 2

Breast: fibrous mound, fat, ducts and glands.

Most cancers START in the UO quadrant: dense fibroglandular tissue (TDLU)

DANGER ZONES where cancers HIDE: medial/inferior breast and retroglandular regions

Question 3

Cooper’s Ligaments

Answer 3

Thin sheets of fascia: hold up breasts
Look like: TINY WHITE LINES on MAMMO
ECHOGENIC lines on US

Architectural distortion: Straightening/ tethering ==> surgical or radial scars and INTRADUCTAL CARCINOMA

Question 4

Breast Asymmtery/ SHRINKING breast

Is it normal?

What’s the most worrying type of cancer

Which features would make you think of cancer

Answer 4

Is normal IF NO other findings (lumps, bumps, skin thickening)

An asymmetric breast –> SHRINKING breast of INVASIVE LOBULAR BREAST CA.

THINK CANCER : If the SIZE DIFFERENCE is NEW OR there is ASYMMETRIC DENSE PARENCHYMA

Question 5

Lobules

Where do most cancers start

Answer 5

TDLU (terminal duct lobule unit): is where most cancers start (UO quadrant)

Ductal calcifications can be linear or segmental and can be cancer

Question 6

Blood and lymphatic drainage

Answer 6

Internal mammary 60%; lat thoracic and IC perforators

Axilla (97%); Internal mammary nodes (3%)

Question 7

Axillary LN levels

What are the anatomic relations of the nodes to the pec min and major

Answer 7

Divided into 3 by pectoralis minor muscle: (see crack pic 456)

Level 1 : Lateral to pec min.
Level 2: Deep to pec min.
Level 3: Above and medial pec min.
Basically lateral to medial

Rotter node: Btw pec min and maj.

Drains from 1 -> 2 -> 3 and -> thorax.

Question 8

Internal Mammary Node

Does it matter if you see it on US?

How common is it to see it on US?

A cancer from which location spreads to the IM node and where else has it already spread?

Answer 8

IF YOU SEE THE INTERNAL MAMMARY NODE on US, ITS ABN and prob a MET!

Isolated mets can occur (3%) and occurs from a MEDIAL cancer and means its ALREADY SPREAD to the axilla/ everywhere.

Question 9

Sternalis muscle (pic 457)- is Shaista aunty

Is it a muscle or a mass?! Work it or biopsy it?

Which view can you see/ not see it?

Answer 9

Non functional muscle, next to sternum, simulates a mass, usually UL, occurs in 5% of people.

ONLY ON CC. NEVER ON MLO.

In real life, see if you can see it on prior imaging. CT preferred.

Question 10

Milk streak

Answer 10

Extra tissue in Axilla (most common)/ Inframammary fold.

Extra nipples in milk streak areas