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Flashcards in test #27 4.16 Deck (157):
1

why does C. perfringens make gas necrosis?

rapid metabolism of muscle tissue carbohydrate --> gas

2

osmium tetroxide

fat = black

3

fat embolism syndrome

(1) respiratory distress
(2) nonfocal neurological disturbance
(3) chest lesions consistent w/ thrombocytopenia

4

describe path of fat emboli

dislodge from bone marrow, enter marrow vascular sinusoids,

- occlude pulmonary microvessels --> impair gas exchange
- occlude vasculature in CNS

5

describe promotion of parenchymal destruction w/ fat emboli (2)

1. platelet & mediators coat & adhere to emboli --> thrombocytopenia
2. systemic activation of LPL (lipoprotein lipase) releases oleic acid systemically --> toxic levels

6

wright stain

often hemotological stain. purple platelets

7

iron stain // hemosiderin

brown on H&E
dark blue on prussian blue

8

second trimester quad screen for down's syndrome:

increased: b-HCG, inhibin A.
decreased: AFP, estriol

9

first trimester findings in down's syndrome:

ultrasound:
increased nuchal translucency &
hypoplastic nasal bone.

serum:
increased b-HCG
decreased PAPP-A

10

edward's syndrome (trisomy 18) screening findings

everything is down.

1st trimester:
DOWN: PAPP-A and b-HCG

quad screen:
DOWN: AFP, b-HCG, estriol, inhibin-A (could be normal)

11

elevated b-HCG and inhibin in 2nd semester?

[low estriol and AFP]

down's syndrome

12

low bHCG, inhibin, estriol, and ADP

edward's syndrome

13

patau syndrome screening findings

first trimester:

DOWN: bHCG, PAPP-A

increased nuchal translucency

14

low b-HCG and PAPP-A w/ nuchal translucency? without nuchal translucency

nuchal translucency: patau

w/o nuchal translucency: edwards

15

vast majority of trisomy 21 occur due to..

nondisjunction in meiosis I
(failure of homologous chromosomes to separate)

16

nondisjunction in meiosis I due to? nondisjunction in meiosis II due to?

meiosis I: failure of homologous chromosomes to separate

meiosis II: failure of sister chromatids to separate

17

lagging strand is CONSTRUCTED in which direction? SYNTHESIZED in which direction?

constructed in 3'->5' direction.

synthesized in 5'->3' direction

18

elder abuse

FIRST: try to speak to patient alone -- to avoid intimidation.

ask:
1. do you feel safe at home
2. who prepares your meals
3. who handles your checkbook

REPORT only after information is collected

19

anovulatory cycles

common in early menarche years.

immature HPA-axis

longer menstrual cycles and irregular bleeding patterns due to presence of anovulatory cycles

no ovulation -> no corpus luteum -> no progesterone -> continuous estrogen

results in continued proliferation.

becomes disorganized, fragile, w/ unstable venous capillaries --> irregular periods of stromal breakdown w/ variable (spotting) & heavy bleeding.

20

three major causes of valvular aortic stenosis. most common world-wide? in USA?

(1) congenitally abnormal valve w/ calcification (i.e. biscuspid)

(2) calcified normal valve

(3) rheumatic heart disease

world-wide: rheumatic heart disease.
US: calcific aortic valve (either bicuspid/tricuspid)

21

right horn of sinus venosus

originally receives blood from IVC. l

becomes smooth part of right atrium.

(smooth part of left from primitive pulmonary vein)

22

bulbos cordis

forms beginning of ventricular outflow tract in embryonic heart. later --> smooth portion of left and right ventricles (adjacent to aorta and pulmonary artery, respectively)

23

primitive atrium

receives blood from sinus venosus in embryonic heart, transmits to primitive ventricle.

primitive atrium --> rough portions of left and right atria

24

close PDA? keep it open?

close: indomethacin.
keep open: PGE2

25

primitive pulmonary vein forms..

smooth part of left atrium

26

left horn of sinus venosus

coronary sinus

right horn --> smooth part of right atrium

27

right common cardinal vein & right anterior cardinal vein

SVC

28

what is the first functional organ in human embryo? when does it function?

fetal heart. begins to pump 4 wks in.

29

first heart loop establishes

left-to-right polarity.

30

patent foramen ovalue

failure of septum primum and septum secundum to fuse. usu left untreated.

31

embryological origin of AV values (tricuspid and mitral)

from fused endocardial cushions of AV canal

32

embryological origin outflow valves (aortic/pulmonary)

endocardial cushion of outflow tract

33

PTH and Ca2+ abnormalities in osteoperosis? osteopetrosis?

NONE

(osteopetrosis might have low Ca2+)

34

PTH and Ca2+ in osteoperosis?

NORMAL

35

high PTH, low Ca2+

renal failure, vitamin D deficiency

36

causes of PTH-independent hypercalcemia?

humoral hypercalcemia of malignancy, vitamin D toxicity, excessive ingestion of Ca2+, thyrotoxicosis, immobilization

37

age of calcification w/ bicuspid aortic valve? tricuspid

bicuspid: premature: 60-70
tricuspid: senile: 80-90

38

damage to common peroneal n. sustained w/? physical finding?

lateral aspect of leg, fibular neck fracture.

foot dropPED & can't feel foot dorsum
(peroneal everts and dorsiflexes)

39

damage to tibial n. sustained w/? physical finding

knee trauma, proximal: baker's cyst. distal: tarsal tunnel.

can't TIP toe & sense sole of foot
tibial inverts and plantar flexes

40

sensation to sole of foot? dorsum?

dorsum: superficial peroneal n.

41

sensation to medial leg? lateral leg?

medial: saphenous n. branch of femoral n.

lateral: superficial peroneal

42

superficial branch of common peroneal?

mostly lateral compartment: foot eversion & sensation of lateral leg & foot dorsum

43

deep branch of common peroneal?

anterior compartment: dorsiflexors of foot and toes. inversion of foot.

sensation to only region between 1st and 2nd digits.

44

where does the coronary sinus reside?

atrioventricular groove on posterior surface.

45

describe placement of biventricular pacemaker

2 leads -> right heart
via left subclavian -> SVC -> right atrium & ventricle

1 lead -> left ventricle
via right atrium -> coronary sinus (atrioventricular groove of posterior heart) -> lateral venous tribituaries

46

swan ganz catheter

insert catheter into pulmonary artery, diagnostic, test for heart failure

47

cataracts, frontal balding, gonadal atrophy, and muscle atrophy / myotonia

myotonic muscular dystrophy type 1. (autosomal dominant)

2nd most common muscular dystrophy (after duchenne's)

48

typical symptom of myotonic muscular dystrophy type 1

difficulty loosening one's grip after handshake. or inability to release doorknob.

49

pathogenesis of myotonic muscular dystrophy

autosomal DOMINANT

CTG repeat expansion in gene for myotonia-protein kinase (DMPK gene)

has anticipation

50

4 diseases w/ trinucleotide expansion

fragile X: CGG
friederich ataxia: GAA
huntington: CAG
myotonic dystrophy: CTG

51

muscle histology in myotonic dystrophy

atrophy of type 1 muscle fibers (esp).

no necrosis or fibrofatty replacement (unlike duchenne's)

52

2 inflammatory myopathy

dermatomyositis and polymyositis

53

ion channel myopathy

myotonia and episodes of hypotonic paralysis. often associated w/ exercise. no atrophy on light microscope.

PAS+ intracytoplasmic inclusions

54

side effect of corticosteroid treatment for atoptic dermatitis?

good: reduces inflammatory response
bad: decreases fibroblast production of ECM collagen and glycosaminoglycans

--> atrophy of dermis w/ loss of collagen, drying, cracking, tightening in skin.
--> also teleangiectasia, ecchymoses from mild trauma, atrophic striae

55

rx for conn syndrome

primary hyperaldosteronism

spironolactone / epeleperone

56

most common CNS tumor in immunosuppresed?

CNS lymphoma

57

describe CNS lymphoma

micropscopically: dense cellular aggregates of uniform, atypical lymphoid cells. majority: B cells.

diffuse large B cell = most common type. (CD20, CD79a+)

associated w/ EBV

nonspecific clinical presentation

usu high grade, poor response to chemo

solitary mass in brain.

58

presentation of sporothrix schenckii. biopsy of innoculation site?

infects immunocompetent!

dimorphic fungi. via thorn pick. spread along lymphatics forming subcutaneous nodules & ulcers

biopsy of innoculation site: granuloma w/ histiocytes, multinucleated giant cells, neutrophils, surrounded by plasma cells.

59

fungus from animal contact?

dermatophytoses -- microsporum species. i.e.

microsporum canis --> tinea capitis

60

woolsorter's disease

pulmonary anthrax!

exposure to animal products (hair, infected hides, hide-based clothing pdt, wool).

GOAT HAIR: most common implicated exposure

61

antiphagocytic D-glutamate capsule?

bacillus anthracis. required for pathogenicity.

62

describe pathogenesis of pulmonary anthrax:

ingested by pulmonary macrophages --> move to mediastinal lymph nodes --> cause hemorrhagic mediastinitis

when spores germinate into vegetative cells, begin to produce 3-part anthrax toxin. symptoms follow.

63

progression of symptoms of pulmonary anthrax

myalgia, fever, malaise.

rapidly progress to hemorrhagic mediastinitis (widened mediastinum on chest x-ray), bloody pleural effusions, septic shock, death

64

hemorrhagic mediastinitis?

pulmonary anthrax

65

long chain "serpentine" or "medusa head" colonies. nonhemolyzing, standard culture medium?

b. anthracis

66

protein A (bind Fc portion of IgG)

staph aureus

67

peritrichous flagella

proteus mirabilis.

flagella distributed uniformly over entire surface of bacterial cell.

characteristic of highly motile organisms.

68

anterior hypothalamic nuclei? destruction?

cooling via parasympathetics. destruction = hyperthermia

69

posterior hypothalamic nuclei? destruction?

heating via sympathetics. destruction = hypothermia

70

ventromedial hypothalamic nuclei? destruction?

satiety.
stimulated by leptin.

destruction = chubs.

71

lateral hypothalamic nuclei? destruction?

hunger.
inhibited by leptin.

destruction = skinny.

72

arcuate nucleus of hypothalamus

secretes:
1. dopamine (inhibit prolactin)
2. GHRH
3. GnRH

73

paraventricular nucleus of hypothalamums

secrete oxytocin, ADH, TRH, CRH

74

supraoptic nucleus of hypothalamus

ADH and oxytoxin

75

suprachiasmatic nucleus

input from retinohypothalamic tract (specialized photosensitive ganglion cells in retina)

secrete NE --> pineal gland --> melatonin

also regulates body temperature and production of cortisol.

regulate circadian rhythm.

76

jetlag

dysynchrony between body's circadian rhythm (sleep/wake cycle) and local environmental rhythm

77

diurnal variation: melatonin levels? cortisol levels

melatonin: high at night, low in day. secreted by pineal gland.

cortisol: high in day, low at night.

78

superficial candidiasis (thrush, esophagitis, cutaneous, vulvovaginitis) directly related to?

hematogenous candidiasis related to?

superficial: low T-LYMPHOCYTE

hematogenous: NEUTROPENIA

79

what type of candida infection are HIV pts susceptible?

what about neutropenic?

HIV: low T count: superficial (oral, cutaneous, etc)

neutropenic: disseminated (right sided endocarditis, liver & kidney abscesses, candidemia)

(note if HIV + neutropenic: susceptible to both)

80

C1 esterase deficifiency

hereditary angioedema

(ACE inhibitors contraindicated)

81

C3 deficiency

(1) recurrent pyogenic sinus, respiratory tract infection.
(2) susceptible to type III HSR

82

C5-9 deficiency

both Neisseria (gonorrhea & meningitidis)

83

nitroglycerin

venodilator (large veins) reduce preload (decreased myocardial oxygen demand and treats angina pectoris)

note: reflex tachycardia and contractility, but overall low O2 demand in heart

84

large veins

modulated by nitroglycerin (venodilate)

85

small arteries & arterioles

primary site of hormonal regulation of systemic blood pressure & site of action of vasoactive antihypertensive drugs (nifedipine and prazosin)

large doses; nitrates affect arteries -- flushing, headache

86

large arteries

primary conduits for blood delivery to tissues. contain large amount of smooth muscle to regulate blood pressure and withstand high pressures

87

precapillary sphincters

bands of smooth muscles at junction of capillary and arteriole. limit flow of blood. respond to NE & E (contract or relax)

also directly responsive to local environment (histamine, low O2, high CO2, decreased pH)

88

equinovarus posture

plantarflexed and inverted
damage to common peroneal n.

paralysis of peroneus longus and peroneus brevis muscle (eversion), tibialis anterior (dorsiflexion), and extrinsic extensors of toe.

89

what three rxns is pyrodoxine B6 important for

(1) transamination and (2) decarboxylation of amino acids. (3) gluconeogenesis.

90

transamination

between amino acid and alpha-keto acid

91

transamination w/ oxaloacetate (alpha-keto-acid) & glutamate (amino acid)

aspartate (amino acid) & alpha-ketoglutarate (keto-acid)

92

transaminases require what cofactor

pyridoxine B6

93

hypertensive crisis defined as..

persistent diastolic pressure exceeding 130mmHg.

associated w/ acute vascular damage

94

hyperplastic arteriolosclerosis histology:

malignant hypertension

onion-like concentric thickening of walls:

due to (1) laminated smooth muscle cells & (2) reduplicated basement membranes

95

major toxicity of statins

hepatoxicity and myopathy (elevated creatinine kinase)

96

statins post MI?

decrease both incidence of 2nd MI and mortality. lower cholesterol & directly stabilize atheromatous plaques

97

statin myopathy amplified w/

concomittant use of fibrates & niacin

98

myopathy-inducing drugs

statins, fibrates, nitrates, hydroxychloroquine, glucocorticoids, colchicine, interferon alpha, penicillinaime.

99

reliability?

reproductability (test, retest).
measured in terms of coefficient of variation (CV) = standard deviation of the set of repeated measurments divided by mean

100

validity (accuracy)?

ability to measure that which it is supposed to measure

(test can be highly reliable but invalid)

101

minute ventillation vs. alveolar ventilation

minute ventilation: total volume of air entering (or leaving) lungs per minute
Ve = Vt x RR

alveolar ventillation: air entering (or leaving) alveoli per minute
Va = (Vt - Vd) x RR

differ on dead space

102

formula for physiological dead space

Vd: Vt x ((PaCO2 x PeCO2)/PaCO2)

Taco, Paco, Peco, Paco

103

what part of bone is usu affected in hematogenous osteomyelitis in children? why?

metaphysis: has slow-flowing sinusoidal vasculature that is conducive to microbial passage.

104

progression of osteomyelitis

seeding event --> acute cellulitis of bone marrow. inflammation in confined boney space leads to increased intramedullarly pressure --> compromises blood flow and forces infectious exudate through vascular chanels into cortex & periosteal region (further compromises blood flow --> ischemia --> necrosis)

can progress to suppurative osteomyelitis (condition where necrotic bone [sequestrum] serves as reservoir for infection and becomes covered by poorly constructed shell of new bone [involcrum]

1+ sinus tracts develop to drain purlent material to soft tissue / out of skin surface

105

how does flat bone (skull, sternum, pelvis) osteomyelitis often occur?

contiguous spread of infection (mastoiditis or dental abscess)

106

most common site for hematogenous osteomyelitis in adults? children?

adult: vertebral body (location of pott's disease, TB)

children: metaphysis of long bone.

(adults less likely to have osteomyelitis bc of changes due to epiphyseal closure)

107

which drugs are metabolized by liver (i.e. affected by inducers / inhibitors)

warfarin, cyclosporine, tacrolimus, phenytoin, isoniazid, rifampin, oral hypoglycemics

108

how do beta-blockers (i.e. timolol) help open-angle glaucoma?

reduce production of aqueous humor by ciliary epithelium

109

what does schlemm's canal drain into

drains into episcleral and conjunctival veins

110

what drugs precipitate narrow angle glaucoma crisis?

anticholinergics (exacerbate small angle in posterior chamber) during mydriasis

111

what drugs reduce aqueous humor production in the eye?

(1) nonselective beta blockers (like timolol)
(2) acetazolamide

112

what drugs increase outflow of aqueous humor

(1) prostaglandin F2a (latanoprost, unoprostone, travoprost)
(2) cholinomimetics (pilocarpine, carbachol)

113

latanoprost, unoprostone, travoprost

prostaglandin F2a. increase drainage of aqueous humor: glaucoma

114

epinephrine & brimonidine for glaucoma

alpha-2 agonists: decreases aqueous humor secretion BUT causes mydriasis.

can use for open angle, but NOT closed angle glaucoma

115

exonuclease vs. endonuclease

exonuclease: remove nucleotide from the END of a DNA molecule

endonuclease: cut DNA at very specific DNA sequences within molecule (i.e. restriction endonucleases)

116

secondary structure (alpha helices & beta sheets) of amino acids dictated by..

hydrogen bonding

-alpha, between every 4th AA
-beta, between all residues of antiparallel strands)

117

tertiary structures form what bonds

many; ionic, hydrophobic, hydrogen, disulfide

118

what is the first step in the pathogenesis of atherosclerosis?

endothelial injury!

(from HTN, hyperlipidemia, smoking, diabetes, homocysteine, toxins (inclu alcohol), viruses, immune rxn)

119

gallstone ileus

rare type of mechanical bowel obstruction, when a large gallstone (> 2.5cm) erodes into the intestinal lumen (via cholecystoenteric fistula)

eventually gets stuck in ileum: smallest lumen in intestinal tract

imaging: pneumobilia (air in billiary tree)

120

GI causes of left pleural effusion

pancreatitis, esophageal rupture

121

progression of irreversible neuronal injury? 12-48 hrs

"red neurons" -- eosinophilic cytoplasm, pynkinotic nuclei, loss of nissl substance

122

progression of irreversible neuronal injury? 24-72 hrs

necrosis & neutrophil invasion

123

progression of irreversible neuronal injury? 3-5 days

macrophage infiltration and phagoytosis

124

progression of irreversible neuronal injury? 1-2wks

reactive gliosis & vascular proliferation around necrotic area

macroscopic: see liquefactive necrosis: well demarcated soft area (1wk-1month)

125

progression of irreversible neuronal injury > 2 wks

glial scar

macroscopic: cystic area surrounded by gliosis (>1 month)

126

severe skin & subcutaneous fat necrosis soon after initiating warfarin?

related to early prothrombotic effects, as warfarin inhibits protein C early (shortest half-life), intitially pro-thrombotic

pronounced w/ high doses of warfarin & patients w/ preexisting protein C deficiency

127

definition of polycythemia in men? women

hematocrit > 52% in men
>48% in women.

128

differentiate between relative vs. absolute polycythemia?

measure RBC mass

129

secondary erythrocytosis can be driven by what level of hypoxia?

SaO2 < 92% (PaO2 < 65 mmHg)

130

'classic' phases of acid secretion within stomach

cephalic: ACh and vagal influence (thought sight, smell)

gastric: mediated by gastrin (which stimulates histamine, and therefore, acid secretion)

intestinal: when protein-containing food enters duodenum. THIS ACTUALLY DOWNREGULATES gastric acid secretion

131

role of the intestinal phase in gastric acid secretion

presence of protein in duodenum actually downregulates acid secretion.

ileum and colon release peptide YY, bind to receptors on ECL cells, inhibits gastrin-stimulated histamine release.

132

receptive relaxation

reflex that allows gastric fundus to dilate in anticipation of food passing through pharynx and esophagus.

133

prostprandial alkaline tide

increase in plasma HCO3- and decrease in plasma Cl- secondary to surge of acid within gastric lumen.

does not play a role in downregulating post-prandial gastric secretion

134

delusional disorder

presence of a NON-BIZARRE delusion for at least one month.

unlikely, but possible, like being followed, cheated, or poisoned (as opposed to covert alien activity)

usu single overriding delusion w/ preserved occupational and social functioning. does not meet diagnostic criteria for SZ

135

paranoid personality vs. delusional disorder

paranoid personality disorder: pervasive pattern of suspiciousness vs. one fixed delusion (delusional disorder)

136

coagulative necrosis

after ischemic injury in most tissue (except brain)

- architecture PRESERVED after death (due to denaturation of lytic enzymes & disrupted proteolysis)
- cell = ANUCLEATED w/ eosinophilic cytoplasm
- leukocytes eventually infiltrate & digest

137

liquefactive necrosis

- seen w/ focal BACTERIAL infection that stimulate MASSIVE leukocyte recruitment
- occurs in CNS infarcts due to LACK of substantive supporting STOMA.

- necrotic cells completely digested by hydrolytic enzymes, forming VISCOUS LIQUID MASS
- often creamy yellow due to dead leukocytes (PUS)
- associated w/ ABSCESS formation in peripheral tissue. brain = CSF-FILLED SPACES

138

fat necrosis

-acute pancreatitis

- release of active pancreatic enzymes, included LIPASES, digest adipose cells & release free fatty acids
- SAPONIFICATION (CHALKY-WHITE DEPOSITS) form when fatty acids combine w/ calcium.

139

Caseous necrosis

- most commonly withTB INFECTION
- also w/ FUNGAL (histo, cryptococcus, coccidioides)

- necrotic tissue = CHEESY TAN-WHITE gross appearance & consists of fragmented cells & acellular proteinaceous material.
- surrounded by macrophages & other inflammatory cells, forming GRANULOMA

140

TB in brain parenchyma

could cause CASEOUS NECROSIS (even though brain is often liquefactive necrosis)

141

fibrinoid necrosis

histologic pattern of injury seen in walls of blood vessels affected by vasculitis syndromes (i.e. polyarteritis nodosa), malignant HTN, and diabetes mellitus

142

nonenzymatic fat necrosis

following trauma, female breast = common example. often mistaken for breast tumor.

143

gallbladder hypomotility? risk factors?

slow / incomplete gallbladder emptying in response to cholecystokinin stimulation

pregnancy, rapid weight loss, prolonged use of parenteral nutrition or ocreotide, high spinal cord injury.

144

describe biliary sludge

consequence of gallbladder hypomotility. results from bile ppt.

contains cholesterol monohydrate crystals, calcium billirubinate, & mucus.

known precursor to stone

acute cholecystitis can occur in 20% of patients w/ biliary sludge.

145

brown GB pigment stones

arise in cases of biliary tract infection

146

black GB pigment stones

arise in causes of intravascular hemolysis

147

cystinuria presents w/ defective transport of..

autosomal recessive
COLA

cysteine, ornithine, lysine, and arginine

148

when does scarlet fever begin post group A strep infection? symptoms?

1-5 days

- fever, malaise, abdominal pain, sore throat
- "strawberry tongue" - inflammed red papillae
- pharynx: erythematous, swollen, covered w/ gray-white exudate

after 1-2 days:
- rash on neck, armpit, groin.
- subsequently generalizes to rest of body

early:
- 'boiled lobster' appearance - scarlet spots / blotches
spread:
- "sandpaper-like" - sunburn w/ goose pimples

cheeks: flushed, giving area around mouth circumoral pallow.

end of 1st wk:
- desquamation in armpits, groin, tips of fingers, toes

predispose to glomerulonephritis / rheumatic fever

149

differentiate kawasaki vs. scarlet fever

tonsilar exudate: scarlet fever

bilateral conjunctivitis: kawasaki

coronary aneursym: kawasaki

both have strawberry red tongue, desquamation

150

3 different neuro manifestations of measles

acute: encephalitis

recovery: acute disseminated encephalomyelitis

years later: subacute sclerosing panencephalitis

151

factor V leiden

DVT, cerebral vein thrombosis, recurrent pregnancy loss.

most common inherited thrombophilia.

hets have 5-10x risk of thrombosis
homoz have 50-100x risk

- factor V has less susceptibility to protein C cleavage
- factor V cannot support activated protein C activity

(increased coag, decreased anticoag)

152

renal artery stenosis primary caused by (2)

atherosclerosis
fibromuscular disease

153

where does malignant melanoma arise

typically skin.

can arise in: eye, esophagus, meninges, mucosal surfaces

risk factors: sun exposure, hereditary, history of pre-existent dysplastic nevus in same location.

154

describe appearance of melanoma gross?

either asymptomatic or pruitic. -

- usu > 1cm.
- demonstrated change in color, size, shape.
- variability in pigment: shades of black, brown, red, navy blue, gray
- borders irregular/notched

155

histology of melanoma?

congregate in poorly formed nests. large w/ irregular nuclei, clumped chromatin. prominent nucleoli.

156

risk of melanoma metastasis

based on growth phase.

radial growth: remain superficial and extend horizontal within epidermis / superficial dermis. no risk of metastasis

vs.

melanoma w/ vertical growth -- atypical immature cells travel down into deep dermal layeres -- increase risk of mets.

157

most important prognostic factor in malignant melanoma?

depth of invasion (breslow thickness)