Breast Path

Question 1

Duct Ectasia

Answer 1

Etiology: plasma cell mastitis, glanulomatous mastitis
Pathogenesis: lactiferous duct clogged/blocked
ROS: nipple retraction, induration (mimics carcinoma)

Question 2

Galactocele

Answer 2

Etiology: cystic dilation of obstructed duct during lactation
ROS: painful lump, could get infected

Question 3

Fibrocystic Change (FCC)

Answer 3

Pathogenesis: cyclical changes assoc w/ menstrual cycle
Morphology: macrocysts
Biopsy: apocrine metaplasia, duct ectasia
ROS: tender, “lumpy bumpy”, NO MALIGNANT POTENTIAL
Mammogram: may show calcification

Question 4

Sclerosis Adenosis

Answer 4

Biopsy: dense fibrous stroma, masses of proliferated terminal ducts
ROS: hard rubbery mass, low risk of malignancy
Mammography: positive for calcification

Question 5

Intraductal Papilloma

Answer 5

Etiology: finger-like projection into lumen of large duct of premenopausal woman
Biopsy: branching papillae in lumen w/ fibrovascular core and double layer of cuboidal cells + outer myoepithelial layer
ROS: bloody nipple d/c

Question 6

Fibroadenoma

Answer 6

Etiology: most common benign tumor of the breast (premenopausal women in their 20s)
Pathogenesis: increase in estrogen
Biopsy: tumor of stromal cells
ROS: single mobile nodule that enlarges in latter part of menstrual cycle or pregnancy
Tx: regression after menopause then calcified

Question 7

Phylloides Tumor

Answer 7

Etiology: stromal hypercellularity (postmenopausal w/ increased risk for malignancy)
Biopsy: leaf-like slits and clefts, hypercellularity w/ atypical (malignant = mitosis >10/HPF)
Complication: hematologic spread, NO lymphadenopathy

Question 8

Risk Factors for Invasive Carcinoma

Answer 8

BRCA-1 or 2 carrier (8X)
Personal hx (2-3X)
FHx (2X)
Obesity
Menopausal status (increased premenopausal)
Time since last biopsy (risk decreases @ 10 yrs)

Question 9

Invasive Breast Cancer

Answer 9

ROS: mass fixed to pectoralis, nipple retraction, lymphedema (Peau d’ orange); mets to lungs, bone, liver, adrenals

Question 10

Ducati Carcinoma In Situ (DCIS)

Answer 10

Etiology: spreads within ducal system
Comedo type: high-grade nuclei w/ central necrosis, toothpaste-like tissue + dystrophic calcification
Complication: Paget Dz

Question 11

Invasive Ductal Carcinoma (IDC)

Answer 11

Etiology: 2/3 express ER/PR and 1/3 overexpress HER2NEU
ROS: frequent retraction of nipple & dimpling of skin
Morphology: desmoplasia leading to white-yellow irregular nodular mass
Biopsy: cords and solid nests w/ anastamosing masses of malignant cells

Question 12

Medullary Carcinoma

Answer 12

Etiology: increased incidence in BRCA1 gene (younger pt’s)
Morphology: soft, fleshy, well-circumscribed mass (2-3cm)
Biopsy: sheets of large anaplastic cells w/ pleomorphic nuclei + lymphoblastic infiltrate (“fried egg” appearance)
Diagnosis: triple negative (ER-/PR-/HER2-) aka Basal Like
Course: responds to regular chemotherapy

Question 13

Colloid (Mucinous) Carcinoma

Answer 13

Etiology: older pt’s w/ good prognosis
Morphology: soft, pale blue-gray
Biopsy: lakes of pale-staining extracellular mucin w/ small islands of tumor cells, mucin dissects into the surrounding stroma

Question 14

Tubular Carcinoma

Answer 14

Etiology: assoc w/ DCIS (40%), LCIS (10%)
Biopsy: well-formed tubules w/ no myoepithelial layer
ROS: <1cm diameter

Question 15

Lobar Carcinoma In Situ (LCIS)

Answer 15

Etiology: incidental finding
Pathogenesis: E-cadherin mutation
Biopsy: loosely cohesive clusters of cells within lobules, intracellular mucin vacuoles
ROS: NO calcifications, BL mass
Complication: 1/3 will eventually develop invasive carcinoma

Question 16

Invasive Lobular Carcinoma (ILC)

Answer 16

Etiology: BL (5-10%)
Morphology: no distinct mass
Biopsy: “Indian file” d/t E-cadherin mutation; “Bull’s Eye” pattern where cells are around normal ducts; signet ring cells
ROS: unique metastasis to CSF/leptomeninges, ovary, uterus, GI

Question 17

Paget’s Dz of the Nipple

Answer 17

Etiology: overexpression of HER2/NEU, underlying intraductal carcinoma
Pathogenesis: DCIS extends up to lactiferous ducts into skin of nipple
Morphology: unilateral eruption w/ scaly crust (mistaken for eczema
Biopsy: Toker cells (large hyeprchromatic nuclei w/ halo that remain in epidermis), Paget cells (same as Toker cells but indicates malignancy invading surrounding area)

Question 18

ER+/PR+ tumor

Answer 18

Responds to Tamoxifen

Question 19

ER-/PR+ tumors

Answer 19

Respond up to 50%

Question 20

ER+/PR-

Answer 20

Respond up to 40%

Question 21

HER2 Status

Answer 21

HER2 shows lack of response to chemotherapy & responds to Herceptin (cannot cross BBB so useless against mets)

Question 22

Male Breast Cancer

Answer 22

Etiology: XXY karyotype, prior breast dz, infertility (BRCA2 mutation), advanced age
Pathogenesis: relative increase in estrogens or reduced androgens (cirrhosis, anabolic steroids, Kleinfelter’s)
Biopsy: intraductal hyperplasia, rapid infiltration
ROS: gynecomastia, Button-like swelling BL

Question 23

Triple Negative IDC

Answer 23

ER-, PR-, HER2-

Not responsive to Tamoxifen or Herceptin

Question 24

Luminal A

Answer 24

ER+ (or PR+) but HER2-

Tx: responds to tamoxifen

Question 25

Luminal B

Answer 25

Aka Triple Positive
ER+, PR+, HER2+
Tx: responds to Tamoxifen and Herceptin

Question 26

Her2+

Answer 26

ER- or PR-

Tx: responds to Herceptin