Breast pathology

Question 1

Features of juvenile fibroadenoma

Answer 1

Increased stromal cellularity
Increased epithelial hyperplasia with gynecomastoid-like micropapillary projections
Fascicular stromal arrangement
Pericanalicular growth pattern
May show rapid growth and large size

Question 2

Describe features of this breast lesion in 8 year old girl.

Dx:

Answer 2

Juvenile fibroadenoma:

• Increased stromal cellularity
• Increased epithelial hyperplasia with gynecomastoid-like micropapillary projections
• Fascicular stromal arrangement
• Pericanalicular growth pattern
• May show rapid growth and large size

Question 3

Answer 3

Usual ductal hyperplasia

There is heterogeneity of epithelial cell size and shape, as well as variability of nuclear size, shape, and location. The lumina are irregular in shape.

Bridges are stretched and thin appearing and nuclei are flattened and parallel to bridges.

Question 4

54F bx right breast for microcalcifications. No palpable mass.

Dx

Key features

Answer 4

Usual ductal hyperplasia

Heterogeneity of epithelial and nuclear size and shape. Lumina are located peripherally. Thin and stretched bridges are present.

Question 5

What ICH staining do you expect for UDH.

Answer 5

mixed phenotype staining for both low-molecular-weight cytokeratins (luminal type: CK7, CK8, and CK18) and high-molecular-weight cytokeratins (basal type: CK5/6, CK14, and 34βE12 [CK903]), the latter in a heterogeneous or mosaic pattern

ER staining is also heterogeneous in UDH, in contrast to the strong, diffuse staining seen in ADH and low-grade ductal carcinoma in situ

Question 6

Bx 54F because of screen-detected microcalifications

Dx?

Answer 6

Columnar cell lesion with focal columnar cell hyperplasia.

Question 7

Answer 7

FEA

shows cuboidal epithelial cells with apical snouts, displaying mild nuclear atypia with rounded, slightly enlarged vesicular nuclei and discernible nucleoli.

Question 8

Bx left breast. 54F

Dx?

Rationale?

Answer 8

Dx: ADH

?: reveals the low-grade cytological monotony of the cells making up the arches and small micropapillary structures. These findings are consistent with the diagnosis of atypical ductal hyperplasia.

Question 9

core needle bx left breast.

Dx/DDx?

Description:

Answer 9

ADH (DDx: Low-grade DCIS)

Description: Intr

Intraductal proliferation with cytological monotony and cribriform, polarized spaces of low-grade ductal carcinoma in situ but due to its limited extent (≤ 2.0 mm) is best classified on core needle biopsy as atypical ductal hyperplasia.

Question 10

65F, excision of palpable nodule.

dx?

Features?

Answer 10

Dx: Adenomyoepithelioma with tubular growth.

Note: biphasic appearance, with glandular structures lined by an inner layer of epithelial cells and an outer layer of prominent clear myoepithelial cells with

Question 11

70F, excision of palpable nodule

Dx.

Features.

Answer 11

Adenomyoepithelioma.

Biphasic appearance. Clear myyoepithelial cells can sometimes be prominent, obscuring the epithelial component.

Question 12

Describe the types of haemartomas that occur in the breast (3)

Answer 12

Adenolipoma: normal ducts/lobules admixed with adipose tissue
Myoid haemartoma: smooth muscle component is prominent
chondrolipomas: chondroid islands exist within adipose tissue

Question 13

LCIS

What are the three subtypes?
Define each:

Answer 13

Classic, pleomorphic and florid.
Classic LCIS is characterized by dyscohesive proliferations of type A and/or type B epithelial cells. Type A cells are small cells with uniform hyperchromatic nuclei, whereas type B cells have slightly larger vesicular nuclei, with mild variability in size and shape and with small nucleoli.
Pleomorphic LCIS is composed of larger cells with marked nuclear pleomorphism, which are > 4 times the size of a lymphocyte / equivalent to the cells of high-grade DCIS, with or without apocrine features.
In florid LCIS, the LCIS cells show the cytological features of classic LCIS, but there is marked distention of TDLUs or ducts, creating a confluent mass-like architecture. Florid LCIS should have at least one of two architectural features: little to no intervening stroma between markedly distended acini of involved TDLUs and a size cut-off point at which an expanded acinus or duct fills an area equivalent to ~40–50 cells in diameter.

Pleormorphic and florid usu a/w microcalcifications

Question 14

LCIS

Which subtypes are associated with invasive carcinoma?

Answer 14

Florid and pleomorphic. (prevalence as high as 87%)

Question 15

LCIS

Discuss staining and limitations of E-cadherin, p120-catenin, b-catenin, ER and HER2 status.

Answer 15

Loss of membranous E-cadherin expression is the characteristic for all forms of LCIS. Approx 15% of invasive lobular lesions, the neoplastic cells have conserved but aberrant E-cadherin expression, and this is recapitulated in LCIS. Therefore, fragmented membranous and/or cytoplasmic aberrant staining should not be used to make a diagnosis of DCIS. LCIS cells exhibit strong, diffuse cytoplasmic staining for p120-catenin and loss of expression of membrane β-catenin. The classic and florid subtypes of LCIS are typically diffusely and strongly positive for ER, have a low Ki-67 proliferation index, and rarely show ERBB2 (HER2) overexpression or gene amplification, or TP53 mutation. The pleomorphic subtype is more likely to be ER-negative (especially apocrine pleomorphic LCIS), may be AR-positive, may demonstrate HER2 overexpression and gene amplification or TP53 mutation, and has a moderate to high Ki-67 proliferation index. Approx 10% cases of pleo are triple (-).

Question 16

Breast bx

Dx?

Answer 16

Classic LCIS.
More than 50% of the acini in a terminal duct lobular unit are filled and expanded by loosely cohesive monomorphic cells with scant cytoplasm and small uniform nuclei.

Question 17

Breast excision

Dx?
Dx criteria?

Answer 17

Pleomorphic LCIS.
Essential: large dyscohesive cells with marked nuclear pleomorphism, > 4 times the size of a lymphocyte / equivalent to the cells of high-grade DCIS, with or without apocrine features.

Desirable: loss of E-cadherin membrane staining.

Question 18

Bx right breast 65F

Dx?
Key features?

Answer 18

Apocrine pleormorphic LCIS.
A subset of pleomorphic lobular carcinoma in situ is further categorized as apocrine type, based on large cells with abundant eosinophilic granular cytoplasm and round to oval nuclei containing prominent nucleoli.

Question 19

breast lesion.

Dx?
Defining features?

Answer 19

Florid lobular carcinoma in situ has cytological features similar to those of classic lobular carcinoma in situ (type A and/or type B cells) but is distinguished by marked expansion of terminal duct lobular units with little to no intervening stroma between markedly distended acini of involved TDLUs, and/or a size cut-off point at which an expanded acinus or duct fills an area equivalent to ~40–50 cells in diameter.

Question 20

39F, R) breast mass at 10 OC 2cm from nipple

Dx?

Answer 20

Tubular adenoma. Largely occur in premenopausal women in UOQ.

Essential: a well-circumscribed tumour composed of a dense proliferation of closely approximated round and oval tubular structures with little background stroma; tubules composed of bilayered ductal and myoepithelial cells.

Desirable: immunohistochemical evaluation for confirmation of the dual cell population by myoepithelial markers (p63, p40, SMA, calponin) and luminal markers (EMA, CK19, CK8/18) if needed.

Tubular adenomas are benign, stable neoplasms with no increased risk of

Question 21

Breast cancer, ductal

Grading?

Answer 21

Nottingham modification of Bloom-Richardson system, based on (a) tumor tubule formation, (b) nuclear pleomorphism and (c) number of mitotic figures in most active areas,
Scoring is done as follows
3 - 5 points: well differentiated (grade I)
6 - 7 points: moderately differentiated (grade II)
8 - 9 points: poorly differentiated (grade III)

Tumor tubule/gland formation:
1 point: > 75% of tumor
2 points: 10 - 75% of tumor
3 points: < 10% of tumor

Nuclear pleomorphism:
1 point: minimal nuclear variation in size and shape (< 1.5 times the size of benign epithelial cell nuclei), even chromatin, inapparent to inconspicuous nucleoli
2 points: moderate nuclear variation in size and shape (1.5 - 2 times the size of benign epithelial cell nuclei), typically visible but small nucleoli
3 points: marked nuclear variation in size and shape (> 2 times the size of benign epithelial cell nuclei), often prominent nucleoli

Question 22

What is HER2? What is the gene and what does it encode?

How is amplification of this gene detected?

Answer 22

HER2/neu is the human epidermal growth factor receptor 2, also called ERBB2 (Erb-B2 receptor tyrosine kinase 2)
HER2 gene encodes transmembrane growth factor receptor (p185).
Cytoplasmic tyrosine kinase is constitutively active when overexpressed due to homo / heterodimerization.

Immunohistochemistry (IHC) detects evidence of protein overexpression via evaluation of the membranous staining in the tumor cells

To detect, the most commonly used in situ hybridization (ISH) is a dual probe fluorescent ISH (FISH) using fluorochrome labeled probes for (a) the HER2 locus on the long arm of chromosome 17 and (b) a site near the centromere of chromosome 17 (CEN17 or CEP17)
In situ hybridization detects HER2 gene amplification as evaluated by counting at least 20 tumor cells and estimating the HER2 copy number and the HER2/CEP17 ratio

Question 23

breast ca AJCC staging

Answer 23

Question 24

breast lesion

dx:
IHC:

Answer 24

Papillary DCIS
Essential: a neoplastic proliferation of epithelial cells covering delicate arborizing fibrovascular cores devoid of myoepithelium but contained within a duct with a surrounding myoepithelial layer.

Desirable: demonstration of the absence of myoepithelium along the fibrovascular cores but presence of myoepithelium along the duct wall by immunohistochemical detection of myoepithelial antigens.

Image: Monotonous cells with low-grade nuclei forming cribriform and glandular spaces line inconspicuous fibrovascular cores.

Question 25

# breast lx Dx Key histo features demonstrated in this image:

Answer 25

Papillary DCIS with a dimorphic population of cells. H&E staining reveals two cell populations. One is luminal with apical snouts. The other, with more-abundant pale cytoplasm, mimics hyperplastic myoepithelium (also called globoid cells); Although most papillary DCIS lesions consist of a single, uniform cell population, papillary DCIS with a dimorphic pattern has also been described. In addition to neoplastic ductal cells, it features a population of cells (globoid cells) with abundant clear cytoplasm; these morphologically resemble myoepithelial cells but have nuclear features and atypia similar to those of the frankly epithelial cell component

Question 26

# breast lesion Dx: Key features exemplified: IHC: What defines invasion in this context?

Answer 26

encapsulated papillary ca Image: A papillary mass within a cystic space with numerous delicate fibrovascular stalks (lined by by a monomorphic population of neoplastic epithelial cells with low- or intermediate-grade nuclei. ) IHC: MEC (-) within and at periphery (can be focally present at periphery), ER/PR/HER2 +/+/-. Frank invasion in this setting is defined as the presence of neoplastic elements that permeate beyond the fibrous capsule with an irregular infiltrative appearance.

Question 27

Describe morphology of solid papillary ca. What is the difference between: SPC in situ vs with invasive vs invasive solid papillary ca?

Answer 27

SPC: characterized by expansile nodules with a solid growth pattern and inconspicuous, delicate fibrovascular cores. monotonous population of round to spindle-shaped epithelial cells with (usually) mild to moderate nuclear atypia and a variable mitotic count. Cells may contain mucin vacuoles. Signet-ring cell features may be prominent. Nuclear palisading around the fibrovascular cores is common. Extracellular mucin production can also be present, but if it is prominent, mucinous carcinoma must be excluded. Solid papillary carcinoma in situ is diagnosed when the nodules have rounded, well-circumscribed contours and a distribution pattern consistent with an in situ process, regardless of whether a myoepithelial cell layer is present around the periphery of the nodules. Solid papillary carcinoma with invasion is diagnosed when solid papillary carcinoma is a/w areas featuring strands or large clusters of tumour cells. SPC w invasion is diagnosed when SPC is associated with areas featuring strands or large clusters of tumour cells. This is frequently seen within pools of extracellular mucin (typically infiltrating the surrounding tissue at the periphery of the lesion), corresponding to mucinous carcinoma. The invasive component may also be of a more conventional type, such as carcinoma of no special type (NST) or lobular, cribriform, or tubular carcinoma { 16625097 }. Invasive SPC is diagnosed when the nodules are devoid of a myoepithelial cell layer and have ragged contours creating a geographical jigsaw pattern within a desmoplastic stroma

Question 28

# solid papillary ca IHC

Answer 28

HMWCK(-); strong & diffuse ER(+); variable PR(+); HER2(-); K67 low->intermediate; SYN + CGN freq (+) (esp when there is an associated mucinous component

Question 29

# breast lesion dx? Key features demonstrated? IHC?

Answer 29

solid papillary ca Expansile nodules with a solid growth pattern have inconspicuous, delicate fibrovascular cores, with no convincing evidence of invasion. IHC: myoep markers (-/+) papillary fronds/periphery of lesion; HMWCK (-) in neoplastic population; ER/PR diffuse strong (+); freq chromo/synapta

Question 30

# breast lesion dx Dx: Key features demonstrated

Answer 30

solid papillary carcinoma High-power view of solid nodules with inconspicuous delicate fibrovascular stalks and a monotonous population of round epithelial cells with low-grade nuclear atypia. In situ: nodules have rounded, well-circumscribed contours and a distribution pattern consistent with an in situ process (regardless of myoepithelial layer around periphery) With invasion: SPC is a/w a convention/mucinous/lobular ca etc Invasive SPC is diagnosed when the nodules have ragged contours

Question 31

# breast lesion Dx? Key feature

Answer 31

solid papillary carcinoma Image: Intracellular mucin (goblet cells) may be prominent in the neoplastic population.

Question 32

# breast lesion dx

Answer 32

Invasive solid papillary carcinoma Nodules devoid of a myoepithelial cell layer with ragged contours create a geographical jigsaw pattern within a desmoplastic stroma or infiltrate the fat.

Question 33

# breast lesion dx

Answer 33

Solid papillary carcinoma with invasive carcinoma Irregular neoplastic glands and trabeculae infiltrate the breast parenchyma adjacent to solid papillary carcinoma.

Question 34

Describe the difference b/w mucinous carcinoma vs mixed mucinous ca vs carcinoma with a mucinous component

Answer 34

Pure MC requires a mucinous component of > 90%; mixed MC has 10–90%. A mucinous component of < 10% should be mentioned.

Question 35

# mucinous carcinoma (of the breast) MC key features: difference b/w type A and type B

Answer 35

MC consists of clusters or sheets of neoplastic cells suspended in abundant extracellular mucin, partitioned by delicate fibrous septa containing capillary blood vessels. The tumour clusters vary in size and shape. Nuclear grade is low or intermediate. Type A = are relatively hypocellular, with a large amount of extracellular mucin, whereas type B MCs tend to be hypercellular and consist of large epithelial clumps or sheets that often show neuroendocrine differentiation

Question 36

breast lesion, dx? IHC DDx:

Answer 36

Type A mucinous carcinoma IHC: ER/PR (+); 80% AR(+); MC and mixed MC WT1 (+); Her2 (-) except in MC where it is amplified > 10% DDx: mucocoele-like lesions (MLLs) with stromal mucin

Question 37

# 27F breast lesion bx dx? diagnostic criteria demographic

Answer 37

lactating adenoma Essential: a well-circumscribed proliferation of closely packed hyperplastic secretory lobules separated by sparse delicate connective tissue; bland-looking lining epithelial cells containing vacuolated or granular cytoplasm and small nuclei with pinpoint uniform nucleoli. demographic: most commonly occurs in 3rd trimester Below: the tubules are lined by single-layered cuboidal epithelial cells with vacuolated cytoplasm and occasional hobnail nuclei, with myoepithelial attenuation. Some dilated tubules contain luminal pink flocculent secretions.

Question 38

# breast lesion dx dx criteria Key features displayed in image

Answer 38

Malignant adenomyoepithelioma Essential: a malignant tumour arising in association with classic AME, with the luminal or myoepithelial component (or both) being malignant. Image: cytological atypia is clearly evident in both epithelial and myoepithelial cells. The myoepithelial cells outnumber the epithelial cells in this case.

Question 39

HER2 amplification Describe how this is assessed using FISH

Answer 39

To detect, the most commonly used in situ hybridization (ISH) is a dual probe fluorescent ISH (FISH) using fluorochrome labeled probes for (a) the HER2 locus on the long arm of chromosome 17 and (b) a site near the centromere of chromosome 17 (CEN17 or CEP17) In situ hybridization detects HER2 gene amplification as evaluated by counting at least 20 tumor cells and estimating the HER2 copy number and the HER2/CEP17 ratio IHC detects protein expression via membraneous staining. Testing must be performed in accredited laboratories Positive: Single probe average HER2 copy number ≥ 6.0 signals/cell Dual probe HER2/CEP17 ratio ≥ 2.0 with any average HER2 copy number, or HER2/CEP17 < 2.0 with an average HER2 copy number ≥ 6.0 signals / cell

Question 40

HER2 IHC Describe assessment

Answer 40

Positive: IHC 3+ (strong positive): tumor displays complete, intense circumferential membranous staining in > 10% of tumor cells (*readily appreciated using a low power objective and observed within a homogenous and contiguous invasive cell population) Equivocal: IHC 2+: weak to moderate complete membrane staining observed in > 10% of invasive tumor cells Negative: IHC 1+: incomplete faint membrane staining and within > 10% of invasive tumor cells IHC 0: no staining observed or incomplete faint / barely perceptible membrane staining within ≤ 10% of invasive tumor cells

Question 41

Nipple lesion Dx? Key features

Answer 41

Syringomatous tumour of the nipple 3 types of cells present Myoepithelial-like cells: p63(+) and high molecular weight keratin (+) Luminal-like cells: p63(-) and low molecular weight keratin (+) Squamoid cells: p63(+) and high molecular weight keratin (+) Cells have small uniform nuclei Mitotic figures absent or rare Infiltrates into smooth muscle of areola Overlying epidermis may be acanthotic

Question 42

# breast ca How do you calculator residual cancer burden following neoadjuvant chemotherapy

Answer 42

Question 43

# clear cell carcinoma of uterine corpus vs ovarian clear cell Histo features and IHC below: clear cell ca uterine corpus (papillary features)

Answer 43

Clear cell carcinoma of uterine corpus: Tubulocystic/papillary/solid; clear to eosinophilic cuboidal, polygonal, hobnail, or flat cells; stratificaiton, intraglandular tufting and detaching budding F+ or absent; squamous differentiation is absent. Nuclear pleomorphism focally moderate to severe. IHC: HNF1beta + (67-100%); napsin A (56-93%); AMACR + (75-88%) Ovarian clear cell: Same architecture as above. Cells are cuboidal and/or hobnail (but not columnar), arranged in a single layer with only minimal stratification. Stromal hyalinization/myxoid stroma are frequent. Solid pattern exhibits sheets of polyhedral cells separated by delicate septa. Cytoplasm- clear to (less commonly) eosinophilic. The glycogen-rich clear cytoplasm is PAS-positive and diastase-sensitive. Nuclei are large and monomorphic, with rounded to angulated contours, hyperchromasia, prominent nucleoli, and (rarely) nuclear pseudoinclusions. Nuclear pleomorphism may be present focally or in scattered cells, but it is typically not diffusely distributed. Mitotic activity is variable but usually low. Hyaline and psammoma bodies are infrequent. A peritumoural and/or diffuse lymphoplasmacytic infiltrate may be present. Essential: a combination of architectural patterns (tubulocystic, papillary, and solid architecture) with flat or cuboidal cells (clear, eosinophilic, hobnail) having uniform nuclear features overall and low mitotic counts. Desirable: associated clear cell adenofibroma; HNF1β and napsin A positivity; WT1 and PR negativity. IHC: PAX8(+); HNV1beta (+); Negative: WT1, ER, PR

Question 44

# uterine serous vs ovarian serous ca IHC

Answer 44

Uterine: p53 aberrant/mutant, p16 (strong/diffuse -> unrelated to HPV infection); CK7 strong membranous staining; Pax8 strong nuclear MMR retained CK20: no expression ER / PR: decreased expression; often negative or focally positive in approximately 50% of cases WT-1: maybe focally positive in 30% of cases; if strong and diffuse, extrauterine serous carcinoma enters the differential Ovarian serous: PAX8, WT1, p16 (~60%), ER (80%), PR (30%), CK7, D2-40 (variable), calretinin (variable, may be focal) Aberrant p53 expression that correlates with TP53 mutation, 3 patterns: Overexpression: strong, diffuse nuclear staining in > 80% of cells (missense mutation) Null phenotype: complete absence of staining (loss of function mutation) Cytoplasmic expression: Cytoplasmic p53 expression with intensity similar to that of internal nuclear controls (loss of function mutation disrupting nuclear localization domain) High Ki67 proliferation index (> 75%) (Oncotarget 2016;8:107877)

Question 45

Dx ? ddx and how you differentiate them How do you grade them/what is their grade Immunoprofile

Answer 45

sclerosing adenosis - has MEC Mixed tumour composed of < 90% tubules (tumours with 10-90% tubules) Radial star (as TC can have a stellate profile at low power, but radial scar has MEC) Graded with the Nottingham criteria and are by definition grade 1 (>90% tubules, uniform small-med nuclei) Immunoprofle: ER+/PR+/HER2-. If HER2 positive, reconsider dx. Usu has luminal profile (LMWCK: CK8/18 (+) CK5/14 (-) Expression of high-molecular-weight cytokeratins and/or ER negativity (especially in small diagnostic biopsies) should raise the possibility of a basal-phenotype carcinoma with tubule formation, such as adenoid cystic carcinoma or low-grade adenosquamous carcinoma.

Question 46

# Malignant phyllodes Diagnosis?

Answer 46

Malignant phyllodes tumours are diagnosed when all of the following features are present: marked stromal nuclear pleomorphism; stromal overgrowth, defined by the absence of epithelial elements in one low-power microscopic field (40× magnification: 4× objective and 10× eyepiece) containing only stroma; increased mitoses (≥ 5 mitoses/mm2; ≥ 10 mitoses per 10 high-power fields of 0.5 mm in diameter and 0.2 mm2 in area); increased stromal cellularity, which is usually diffuse; and an infiltrative border

Question 47

breast mass 60F Dx

Answer 47

invasive pleomorphic lobular carcinoma

Question 48

# papillary lesions Define the categories of papillary lesions of the breast

Answer 48

Question 49

# palpable mass dx? Key features

Answer 49

Solid papillary carcinoma characterized by a solid growth pattern with delicate fibrovascular cores. They frequently show neuroendocrine differentiation and are biologically indolent. Entire lesion occupied by a cell population with cytological features of low or intermediate nuclear grade, growing predominantly in a solid manner; spindle cell component; neuroendocrine and mucinous differentiation is frequent

Question 50

# palpable mass 63F breast

Answer 50

Solid papillary carcinoma with prominent intracellular mucin

Question 51

# mucinous carcinoma Essential diagnostic criteria px compared to IDC, NOS

Answer 51

Essential: Pure MC is characterized by a > 90% mucinous component, with clusters of epithelial tumour cells of low to intermediate nuclear grade, suspended in pools of extracellular mucin; usually ER/PR-positive; HER2-negative. Better px with low rates of local and distant recurrences and excellent 5 year survival rates

Question 52

# malignant spindle cell lesions in the breast ddx

Answer 52

Metaplastic spindel cell carcinoma Malignant phyllodes Primary breast sarcomas: Angiosarcoma; liposarcoma; post-irradiation sarcomas; others (rare!) - leiomyosarcoma, MFH, SFT Metastatic sarcomas

Question 53

Atypical vascular lesion diagnostic features

Answer 53

Question 54

AVL vs angiosarcoma

Answer 54

Question 55

# IHC and special stains for Pagets and ddx for pagets w/ IHC

Answer 55

Intracellular mucin CK7 and cam 5.2 (+) HER2 (+) in 80-90% ER 40% and PR 30%

Question 56

HER IHC interpretation ?

Answer 56

Question 57

What is Rosen triad?

Answer 57

Rosen triad: the presence of tubular carcinoma, columnar cell lesions and LCIS / ALH Initial morphologic observation of lesions that are genetically linked

Question 58

cystic neutrophilic granulomatous mastitis: Key features and causative organisms?

Answer 58

Most patients are women, parous or currently pregnant Characteristic morphologic features include granulomas comprised of epithelioid histiocytes and giant cells with central lipid vacuoles containing gram positive bacteria and rimmed by neutrophils Association with Corynebacterium species, especially Corynebacterium kroppenstedtii, although microbiologic evidence can be difficult to obtain Prolonged antibiotic therapy required for complete resolution

Question 59

What cytogenetic alteration is associated with the low-grade neoplasia pathway in breast?

Answer 59

loss of 16q

Question 60

define prognostic vs predictive factors in breast ca

Answer 60

Prognostic factors in breast ca are those that define the natural hx or outcomes of the disease. Predictive factors: in breast ca are those that are a/w the likelihood of benefit from a specific tx.

Question 61

lymphocytic (diabetic) mastitis/mastopathy: triad of features?

Answer 61

Histologic triad of keloidal type fibrosis, lymphocytic inflammation and epithelioid myofibroblasts

Question 62

Incidental microscopic finding. Dx?

Answer 62

Perilobular hemangioma conglomerate of small, thin walled capillary vessels in and around a lobule Usu < 2mm and incidental finding. Not to be mistaken for angiosarcoma

Question 63

Describe morphological features of breast cancers assoc with BRCA1 mutation carriers?

Answer 63

Tumors arising in BRCA1 mutation carriers are of higher nuclear and Nottingham grades, more often a/w a prominent lymphocytic infiltrate and demonstrate scant DCIS. BRCA1 associated tumors are usu invasive breast ca NST with medullary pattern (well demarcated, solid nests, with necrosis), or metaplatic carcinoma.

Question 64

Cancer syndromes associated with breast cancer

Answer 64

BRCA1/2 (TSP engaged in the homologous recombination repair pathway to repair DNA breaks) Li-Fraumeni (TP53) - p53 is TSP stimulates downstream pathways leading to protective processes such as celll cycle arrest apoptosis and senescence. Germline mutations in CDH1 (ILC)

Question 65

what are the features of diabetic mastopathy?

Answer 65

Histologic triad of keloidal type fibrosis, lymphocytic infiltrates and epithelioid stromal myofibroblasts Associated with type I (insulin dependent) diabetes or other autoimmune diseases

Question 66

features of a mucocele-like lesion?

Answer 66

Rare lesion characterized by dilated epithelium lined ducts filled with mucin; associated with extravasation of acellular mucin into the stroma Cysts lined by flat or low cuboidal epithelium

Question 67

define the morphology of pleomorphic lobular carcinoma

Answer 67

Pleomorphic lobular carcinoma (PLC) retains the distinctive growth pattern of lobular carcinoma but exhibits a greater degree of pleomorphism (defined as larger cells with marked nuclear pleomorphism, > 4 times the size of lymphocytes / equivalent to that of high-grade ductal carcinoma in situ, with or without apocrine features) { 12379750 } and a higher mitotic count than classic ILC