repro. Mehl. breast neoplasia

Question 1

Most common malignant (ie has metastatic potential) breast cancer?

Answer 1

DCIS

Question 2

microcalcifications in mammography = ?

Answer 2

DCIS till proven otherwise

Question 3

DCIS. next best step?

Answer 3

needle-guided open biopsy

FNA is wrong

Question 4

DCIS. related disease?

Answer 4

Paget disease of breast (looks like a nipple with eczema in patient over 50) is often the cutaneous extension of an underlying DCIS.

Question 5

Invasive ductal. Invasive form of ductal carcinoma. what is seen on biopsy?

Answer 5

Cells on biopsy have stellate morphology.

Question 6

LCIS. Same as DCIS, malignant potential but not yet invaded.

Answer 6

.

Question 7

LCIS. on histo looks like how?

Answer 7

Appears as linear rows of cells (“Indian file”) on histo.

Question 8

LCIS. This (on histo) is supposedly due to decr. E-cadherin expression, where the cells don’t clump together the same way they do as with ductal carcinomas.
I haven’t seen USMLE give a fuck about this detail, but I’m mentioning it because if you ever talk to an attending about breast cancers, they become like hysterical over this detail.

Answer 8

.

Question 9

Invasive lobular. how percent bilateral?

Answer 9

Invasive form of lobular carcinoma.
20-30% bilateral.

Question 10

Intraductal papilloma. definition?

Answer 10

Unilateral bloody/rusty nipple discharge = intraductal papilloma till proven otherwise.

Question 11

Inflammatory carcinoma. CP?

Answer 11

Can appear as a red/inflamed breast, as though there’s an infection.

Rubor (redness), dolor (pain), tumor (swelling), calor (heat).

Question 12

Inflammatory carcinoma.

Answer 12

Peau d’orange is an orange peel-appearing texture of the breast due to
tethering of the skin by Coopers ligaments in the setting of blockage of
lymphatic drainage by tumor cells.

Question 13

Comedocarcinoma.

Cancer with cheese-like consistency. Nonexistent on USMLE. Don’t think I’ve ever seen it assessed.

Answer 13

.

Question 14

Medullary carcinoma.
- Another nonsense / garbage diagnosis on USMLE.
- Mentioning comedo- and medullary carcinomas because if I don’t, then at
some point I’ll get some whiny/mousy DMs from students about why I didn’t
mention them.

Answer 14

.

Question 15

most common breast tumor overall?

Answer 15

Fibroadenoma. benign

Question 16

Fibroadenoma. CP?

Answer 16

Presents as rubbery, mobile, non-tender breast lump in woman 20s-30s.

Question 17

Fibroadenoma. CP on UG?

Answer 17

Will appear as solid breast mass without calcification on ultrasound.

Question 18

Fibroadenoma. BEST NEXT STEP?

Answer 18

FNA is next best step to confirm Dx. If confirmed fibroadenoma, they do not
need to be excised.

Question 19

Cystosarcoma phyllodes. CP? on microscopy?

Answer 19

Fast-growing breast lesion that appears “leaf-like” on light microscopy.

Can be benign or malignant based on histo.

Question 20

BRCA points. inheritance in what fasion?

Answer 20

BRCA 1/2 are tumor suppressor genes but are inherited in an autosomal
dominant fashion with incomplete penetrance (i.e., sometimes can skip a
generation). A pedigree requiring you know this pattern is asked on NBME.

Question 21

BRCA points. what nbme wants you also know? apie molecular mechanism

Answer 21

NBME also wants you to know that, with BRCA mutations, the molecular
process that’s fucked up is “recombinational double-stranded DNA repair.”