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Block 2 > Path 2 > Flashcards

Path 2 Flashcards

1
Q

dermatomyositis affects? classic vs revised model

A

skin & muscles. humoral attack on muscle capillaries and arterioles –> MAC deposits in perivascular sites –> capillaries destroyed and muscle fibers atrophy vs overprod of IFN-inducible proteins –> high type I IFN –> endothelial cells and muscle fibers injured –> perifascicular atrophy

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2
Q

skin vs muscle vs constitutional sxs of DM

A

gottron papules, Heliotrope eruption; facial erythema; poikiloderma at Shawl/V neck/Holster sign; nailfold abnlities vs slow progressive prox muscle weakness vs interstitial lung dz, dysphagia, heart, polyarthritis/joints

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3
Q

DM subtypes: Clinically amyopathic DM vs juvenile DM vs malig-assoc DM

A

no skin sxs vs <18yo vs adenocarcinoma to cvx, lung, ovaries, pancreas, bladder, stomach; Myositis-specific ag = highly expressed in ca tissue –> immune rxns against ca cross-react w/ skel muscle fibers –> myositis

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4
Q

DM ab: antiMi2 vs antiJo1 vs antip155/140

A

against DNA helicase; exclusive in DM vs against histidyl tRNA synthetase; more common in PM vs against transcpxn factor for cellular differentiation; more common in malig associated DM

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5
Q

PM affects? Perforin pathway. any perifascicular atrophy of infiltrates?

A

skin. Perforin and granzyme granules of CD8 cells = directed towards healthy muscle fibers w/ MHC I –> necrosis. no b/c not DM

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6
Q

PM muscle vs constitutional sxs

A

Symmetrical, proximal muscle weakness in UE and LE; Facial and ocular muscles not affected vs Lung, heart, oropharynx, joints

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7
Q

PM subtypes: juvenile PM vs malig assoc PM

A

<18yo vs Colorectal, lung, hepatic ca

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8
Q

PM labs: ANA vs Anti Jo1 ab vs Anti-signal recognition particle (SRP) ab

A

nonspecific for inflamm or autoimmune vs against histidyl tRNA synthetase vs targets cytosolic protein-RNA complex that couples synthesis of nascent proteins to their proper membrane localization

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9
Q

how to tx PM?

A

glucocorticoid

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10
Q

Inclusion body myositis affects? Hallmark?

A

muscles. rimmed autophagic vacuoles containing protein aggregates like in degen dzs –> degen theory of s-IBM

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11
Q

proteins found in IBM

A

intracellular amyloid that’s immunoreactive to β-amyloid protein; phosphorylated tau, α-synuclein, ubiquitin, presenilin

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12
Q

IBM sxs

A

Asymmetrical slow progressive weakness of distal and proximal muscles
* Weak quads, finger dexterity, and grip strength
* Atrophy of quads and forearm flexors

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13
Q

IBM labs: high CK vs Anti-cytosolic 5’-nucleotidase (cN1A) ab

A

blank vs colocalize w/ granular intravacuole deposits and vacuole rims
* Exclusive in inclusion-body myositis

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14
Q

how to tx IBM?

A

glucocorticoids, wheelchair by 10yo

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15
Q

IBM has autoimmune pathogenesis by?

A

CD8 cell, B cell, anti-cN1A ab

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16
Q

What is immune-mediated necrotizing myopathy? any CD8 cells (PM/IBM) or perifascicular atrophy (DM) involved?

A

muscle fiber degeneration, necrosis, regeneration. no

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17
Q

IMNM skin vs muscle vs constitutional sxs

A

gottron, heliotrope, V sign vs prox muscle weakness vs interstitial lung dz, unknown malig risk

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18
Q

how to dx IMNM?

A

muscle bx: more necrosis, less inflamm/phag but macs can be seen around necrotic fibers

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19
Q

IMNM labs: High CK; Nml or high ESR, CRP vs Anti-SRP ab vs Anti-HMGCR ab

A

self explanatory vs triggered by VZV, HPV; targets cytosolic protein-RNA complex that couples synthesis of nascent proteins to their proper membrane localization vs Triggered by statins

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20
Q

how to tx IMNM?

A

Corticosteroids w/ methotrexate; mortality rte 2-3x higher than gen pop

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21
Q

metabolic myopathies

A

auto rec d/o leading to insufficient energy prod d/t defect of glycogen, lipid, or mito metab

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22
Q

Disorders of glycogen metab

A

mutations in genes encoding proteins for glycogen synthesis or degradation –> glycogen can accumulate in tissue

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23
Q

GSD Type II/Pompe dz

A

Mutation in GAA gene encoding acid α-glycosidase (lysosome) deficiency –> glycogen accumulates in lysosomes of skel or cardiac muscle cells –> enlarged lysosomes –> compressed cell organelles –> injure and replace muscle fibers –> dec cardiac and muscle fxn

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24
Q

Pompe dz clinical pres: infant onset vs late onset

A

1-5% of residual α-glycosidase activity; cardiomegaly, resp distress, muscle weakness, failure to thrive vs 15-40% of residual α-glycosidase activity; no cardiomegaly, resp fail d/t diaphragm, muscle weakness in limb girdle distribution (prox muscle most affected)

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25
Q

pathology of Pompe dz: light vs e- microscopy

A

vacuolar myopathy that stain pos for glycogen w/ PAS stain vs see glycogen in enlarged lysosomes –> injured muscle fibers

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26
Q

how to dx vs tx Pompe dz?

A

Measuring GAA enzyme activity in cultured skin fibroblasts or peripheral blood lymphocytes, high CK vs enzyme replacement therapy

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27
Q

GSD Type V/McArdle dz

A

Mutation in PYGM gene encoding myophosphorylase –> deficiency –> subsarcolemmal deposits of excess glycogen in periphery of fibers –> dec ATP b/c no glycogenolysis –> inc inorganic phosphate Pi in skel muscle –> inhibit ion pumps –> dec cellular integrity, muscle fiber dmg, rhabdomyolysis

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28
Q

McArdle dz clinical pres

A
  • Exer intolerance in 1st decade of life
  • Fatigue, severe muscle cramps relieved by rest
  • Muscle contracture –> rhabdomyolysis
  • Myoglobinuria –> acute renal failure requiring dialysis
  • Second wind phenomenon = sxs subside d/t switch to alternative extramuscular fuel substrates for muscle metab
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29
Q

how to dx McArdle dz?

A

genetic test of PGYM gene; o Biochemical assay of myophosphorylase activity if genetic test unclear; Forearm exer test (flat lactate curve); high CK, myoglobinuria

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30
Q

how to tx McArdle dz?

A

no specific tx –> aerobic conditioning, high carb diet

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31
Q

disorders of lipid metabl

A

Carnitine palmitoyltransferase II deficiency: auto rec mutation of CPT2 gene –> deficiency –> dec mito beta-oxidation of long chain FA –> dec acetyl CoA synthesis –> insufficient energy output in liver, skel muscle, heart –> steatosis in liver, skel muscle, heart, renal tube epithelium; lipid accumulation in skel muscle; life-threatening cardiac arrhythmia

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32
Q

d/o of lipid metab clinical pres: myopathic vs severe infantile vs neonatal

A

most common and benign; 6-20yo, myoglobinuria by prolonged exer, High CK, No acute muscle or liver dysfunction vs 6mo-2yo; Liver failure w/ hypoketotic hypoglycemia, Cardiomyopathy and peripheral myopathy vs * Days after birth; Liver failure w/ hypoketotic hypoglycemia, Cardiomyopathy, Sz, Congenital anomalies

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33
Q

mito myopathies

A

muscle weakness and fatigue d/t defect in mito or in resp chain

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34
Q

what does resp chain consist of?

A

o 5 multimeric complexes in inner mito membrane
o 2 small e- carriers (CoQ10, cytochrome c)

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35
Q

describe mtDNA

A

small circular 2x stranded molec encoding 13 proteins of resp chain and RNA machinery for translation; High rate of spont mutations, Lack NER mechanism to repair mutations, maternal inheritance

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36
Q

Chronic progressive external ophthalmoplegia

A

slow progressive paralysis of extraocular and eyelid muscles

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37
Q

which 3 mutations are found in external ophthalmoplegia?

A

o Auto dom mutation in TWNK and SLC25A4 genes
o Auto dom or rec mutation in POLG and RRM2B genes
o Mito point mutation in MTTL1 gene

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38
Q

external ophthalmoplegia clinical pres

A

bil ptosis, limited eye movements, face/neck flexors, sometimes limb and bulbar muscle movement, sensorineural hearing loss

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39
Q

how to dx external ophthalmoplegia (3)?

A

DNA analysis of gene mutations in mtDNA (large deletion) and nDNA; High CK, blood lactate, alanine, Abnl urine organic acid; US/CT/MRI shows thin extraocular muscles

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40
Q

Kearns-Sayre syndrome

A

multisystem d/o of progressive external ophthalmoplegia, cardiac conduction block and retinitis pigmentosa; more severe than CPEO

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41
Q

what is cardiac conduction block vs retinitis pigmentosa of Kearns-Sayre syndrome?

A

d/t distal His bundle and bundle branches losing myofibrils and excess mito –> cardiac death vs Retinitis pigmentosa = progressive degen of rod photoreceptor cells in retina –> severe vision impairment

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42
Q

Infectious arthritis/septic arthritis/suppurative arthritis/purulent arthritis

A

synovial inflammation d/t invasion of joint space by microorganisms

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43
Q

gram pos vs neg pathogens causing nongono arthritis

A

Staph aureus and Streptococcus (pyogenes > pneumoniae) vs H. influenzae, E. coli, Pseudomonas aeruginosa (IVDU), Salmonella (sickle cell)

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44
Q

risk factors of nongono arthritis

A

o Large > small joints, males > females, children > adults

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45
Q

causes of nongono arthritis (4)

A
  • Hematogenous spread into synovial capillaries
  • Spread from contiguous infected foci like epiphyseal osteomyelitis
  • Spread from neighboring soft-tissue infxn
  • Direction inoculation of bacteria thru arthrocentesis, corticosteroid injection, arthroscopy
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46
Q

does synovial tissue have basement membrane?

A

no –> microorgs can access synovial fluid easily –> inflamm and joint effusion –> release TNF alpha, IL1/6/8, neu/macs –> dmg synovium & cartilage –> abscess

47
Q

nongono arthritis clinical pres

A

 Fever, intense joint pin, malaise in 1-2 wk period
 Joint = erythematous, warm, swollen, effusion, dec ROM
 Avascular necrosis of femoral head

48
Q

how to dx nongono arthritis (4)

A

 Gram stain of synovial fluid
 PCR for neg cx
 US shows joint effusions, XR shows joint space narrowing, MRI shows joint effusion w/ bone marrow edema, cartilage destruction
 Synovial fluid count >50k cells, low glu

49
Q

cause of gono arthritis

A

o By hematogenous spread of gram neg diplococci N. gonorrheae –> disseminated gonococcal infxn

50
Q

gono arthritis virulence factors

A
  • Porin B isoform 1A
  • AHU auxotype strains
  • Strains w/ unique genetic islands
  • Strains that don’t express Opa proteins
  • Strains that express pili w/ polyG tract
51
Q

2 major clinical syndromes of gono arthritis

A

tenosynovitis (inflmm of tendon sheath), dermatitis, polyarthralgia. purulent arthritis (mono or oligoarthritis w/ pain, erythema, dec ROM in 1+ joints)

52
Q

how to dx gono arthritis?

A

blood cx shows N. gonorrheae, mild leukocytosis and ESR

53
Q

bacteria causing acute vs chronic arthritis

A

pyogenic bacteria, viruses vs Mycobacterium tuberculosis, non-Candida fungi, spirochetes

54
Q

Tuberculous spondylitis/Pott dz

A

involves vertebral body or intervertebral discs by TB, usually thoracic or lumbar; no destruction b/c no proteolytic enzymes

55
Q

how does thoracic vs lumbar present in Pott dz?

A
  • Cold abscess starts as fusiform or bulbous paraspinal swelling
    vs
  • Cold abscess starts as groin swelling and descend below inguinal ligament to medial thigh
56
Q

Pott dz clinical pres (4)

A

 Insidious onset and slow progression
 Pain and tenderness at site
 Tuberculous/cold abscess
 Spinal deformity (Gibbus deformity = kyphosis w/ sharp angulation d/t slow collapse of 1+ vertebral bodies –> cord compression)

57
Q

Pott dz labs

A

 High ESR and CP, leuk count nml

58
Q

TB arthritis. clinical pres vs labs

A

monoarthritis usually in hip or knee. Joint pain, No fever or systemic sxs, Phemister triad: periarticular osteoporosis, peripherally located osseous erosion, gradual joint space narrowing vs High leuk count, low glu, Pos cx, Caseous granulomas

59
Q

Lyme arthritis/Lyme dz

A

Borrelia (B. burgdorferi from Ixodes ticks in America, B. afzelli and garinii in Europe)

60
Q

early local vs early dissem vs late dissem vs PTLDS

A

erythema migrans (red nonitchy painless macule) –> can tx w/ abx vs EM, AV heart block, fever, facial nerve neuritis w/ facial nerve palsy, acute septic meningitis w/ stiff neck vs Monoarticular arthritis in large joints –> warm effused joints; Pannus development like in RA; Synovial fluid shows high leuk count, no live B. burgdorferi vs Fever, difficulty sleeping, arthralgia, myalgia, memory impairment, HA; can range from mild to severe

61
Q

how to dx lyme arthritis/dz?

A

ELISA –> igM western blot

62
Q

viral arthritis example: direct invasion of joint space by Chikungunya

A
  • Chikungunya virus = arthropod alphavirus transmitted to human by infected Aedes mosquitoes
    o Chikungunya fever = triad of acute febrile illness, severe symmetrical polyarthralgia/arthritis, maculopapular rash
63
Q

viral arthritis example: immune complex formation by parvovirus 19

A
  • Parvovirus B19 = transmitted to humans by aerosolized infected respiratory droplets
    o Erythema infectiosum = self-limited febrile rash-producing dz
     Biphasic but no joint destruction: Fever and nonspecific flu-like sxs; Erythematous malar/slapped cheek rash and Acute onset symmetric polyarthritis Involveing small joints of hands and wrists
    (Has detectable antiviral ab)
     Sxs resolve in 3wks
64
Q

viruses that spread hematogenously to form immune complexes –> arthritis?

A
  • Parvovirus B19, HepB/C, Rubella, measles/mumps, HIV1, HTLV1
65
Q

how to dx viral arthritis?

A

o IgM serologic testing then IgG serologic testing
o Isolation of virus from synovium

66
Q

Rheumatoid arthritis

A

chronic, immune mediated, systemic inflammatory dz involving synovial joints

67
Q

RA clinical presentation

A

slow gradual onset;
 PIP, MCP, wrist, elbow, shoulder
 MTP, ankle, knee
 Hip, cervical spine, temporomandibular
 Swelling, pain, warmth, dec ROM

68
Q

RA deformities: ulnar deviation of fingers vs Swan neck deformity vs Boutonniere deformity

A

blank vs Hyperextension of PIP and flexion of DIP d/t laxity of PIP vs Hyperextension of MCP, hyperflexion of PIP, hyperextension of DIP

69
Q

RA: skin vs heart vs vasculitis

A
  • Palpable subq nodule/rheumatoid nodule
  • Vasculitic lesion –> palpable purpura, skin ulcer, digital infarct
    vs
  • Rheumatoid nodules in epicardium, myocardium, valves –> valve dz and heart block
  • Angina, MI
    vs
  • Necrotizing vasculitis of small and medium vessels in diff viscera
  • Skin, finger, peripheral nerves
70
Q

RA: lungs vs eyes vs kidney vs Felty syndrome

A

Rheumatoid nodules in lungs –> Pleural effusion, interstitial lung fibrosis vs Keratoconjunctivitis sicca, Epi/scleritis vs Systemic AA amyloidosis vs triad of seropos RA, neutropenia, splenomegaly

71
Q

how to dx RA?

A

o Inflamm arthritis involving 3+ joints, symmetric involvement of MCP and PIP, pos RF and/or anti-CCP, high ESR or CRP, sxs last 6+ wks

72
Q

How are you “seroneg RA”? is RF specific?

A

o Pts w/ neg RF and anti-CCP but pos for all others. no –> SLE, scleroderma, Sjorgen, infxn

73
Q

RA labs: acute phase vs hematologic vs autoimmune ab vs synovial fluid

A

high ESR, CRP, RA vs anemia, mild leukocytosis vs RF, antiCCP, ANA vs sl cloudy, yellow, no cx

74
Q

RA imging

A

joint space narrowing b/c articular cartilage destruction, bone erosion –> irreversible dmg

75
Q

how to tx RA?

A

NSAIDS, DMARDS, corticosteroids, immunosuppressants

76
Q

juvenile idiopathic arthritis

A

all forms of arthritis <16yo, persists 6+ wks, unknown cause

77
Q

JIA: oligoarticular vs polyarticular vs undifferentiated

A

 </= 4 joints during 1st 6mo of dz
 LE, no small joints
 RF neg, ANA pos
vs
 >/= 5 joints
 Symmetric involvement of fingers, wrists, knees, ankles
 RF neg –> better prognosis, RF pos –> similar to adult RA
 ANA pos
vs
 Don’t meet criteria of one or meet mult criteria of each

78
Q

JIA: Enthesitis-related arthritis vs psoriatic vs systemic/Still dz

A

 Joints and entheses (insertions of tendons and ligaments)
* Achilles tendon
* Ankylosing spondylitis, reactive arthritis
 RF and ANA neg
vs
 Polyarthritis w/ psoriasis, dactylitis/SI-itis/enthesitis, DIP, nails, conjunctivitis/uveitis, aortic regurg
 RF neg
vs
 Fever, macular skin rash, lymphadenopathy, hepatosplenomegaly, serositis
 RF and ANA neg

79
Q

JIA labs. how to tx JIA?

A

High ESR; RF, ANA, HLA-B27 distinguish types. Tx same as RA

80
Q

ganglion cyst vs synovial cyst vs Baker’s/popliteal cyst

A

pseudocyst of dense fibrous connective tissue w/ gelatinous fluid, hyaluronic acid, mucopolysacch, and w/o synovial cells vs true cyst w/ synovial fluid and synovial cells; can coexist w/ OA, RA, meniscus tears vs most common type of synovial cyst in popliteal fossa d/t distention of gastrocnemius

81
Q

tenosynovial giant cell tumor

A

benign locally aggressive tumors of joints, bursae, tendon sheaths; t(1;2)(p13;q37); mutation –> upreg CSF1 gene –> inc monocyte colony-stimulating factor 1 –> inc macs

82
Q

localized vs diffuse/pigmented villonodular synovitis

A

both pain, swelling, dec ROM. red/brown nodules of Mononuclear cells/neoplastic synoviocytes, histiocytes, osteoclast-like multinucleated giant cell, lipid-laden macs; Surrounded by thin fibrous capsule; Thumb, index and middle finger vs Red-brown mass over hyperplastic synovium with villonodular growth pattern –> covers entire synovial membrane; knee > hip > ankle > shoulder > elbow

83
Q

soft tissue tumors

A

from pluripotent mesenchymal stem cells residing in soft tissues

84
Q

lipoma

A

t(3;12)(q27-28;q13-14) –> fusing HMGA2 gene w/ LPP gene; Yellow doughy tumors made of mature univacuolated adipocytes w/ minimal variation in size; Superficial lipomas in subq tissue > deep lipomas in muscle > visceral lipomas in resp tract, GI tract, intracranial space

85
Q

liposarcoma: well diff vs myxoid vs pleomorphic

A

Amplification of chrm12 q13-q15 –> inc MDM2 gene –> neg regulator of P53 vs * Translocation t(12;16)(q13;p11) –>FUS-CHOP gene fusion –> blocks differentiation of adipocyte precursors –> immature adipocytes in continuous cycle of prolif w/o differentiation vs complex chrm abnormalities. Thigh > limb girdle > upper limb > retroperitoneum

86
Q

tumors of fibrous tissue: look at study guide

A

yep

87
Q

tumors of skel muscle: rhabdomyosarcoma

A

in children
 Soft tissue sarcoma w/ skel muscle differentiation
 Loss of heterozygosity of chrm 11p15 –> inc IGF-2 gene –> inc growth of RMS cells

88
Q

rhabdomyosarcoma: embryonal vs alveolar vs pleomorphic vs spindle cell

A
  • Densely packed hypercellular areas of small undifferentiated cells alt w/ hypocellular myxoid areas
  • GU, head, neck
    vs
  • Primitive round cells forming conglomerates similar looking to lung alveoli
  • Extremities, trunk, perianal
    vs
  • Large, atypical, multinucleated polygonal eosinophilic cells
  • Extremities, trunk
    vs
  • Fascicles of spindle cells embedded in collagen stroma
  • Paratesticular
89
Q

tumors of smooth muscle: look at study guide

A

yep

90
Q

tumors of uncertain histogenesis: synovial sarcoma vs undifferentiated pleomorphic sarcoma

A

NOT from synovial membrane –> from multipotent stem cells capable of differentiating to mono/biphasic mesenchymal spindle and/or epithelial cuboid cells (cuboid cell = PAS pos)
t(X;18)(p11.2;q11.2) –> fusion of SS18 gene and SSX gene –> large mass in deep soft tissue
vs
* Storiform = plump spindle cells arrange in short fascicles in cartwheel pattern
* Pleomorphic pattern = plumper fibroblastic cells and rounded histiocyte-like cells

91
Q

osteoid osteoma & osteoblastoma. XR shows?

A

Translocation of FOS oncogene encoding transcpxn factor –> overexpression of FOS protein in osteoblasts –> dull achy pain. small round central radiolucency (central nidus) made of osteoid trabeculae w/ peripheral sclerotic dense bone

92
Q

osteosarcoma

A

most common malig tumor from osteoid or immature bone made by tumor cells; * Loss of fxn mutation in RB gene encoding retinoblastoma protein or loss of fxn mutation in TP53 gene encoding p53 protein –> inactivate CDKN2A gene encoding tumor suppressors p16 & p14, AND overexpressing MDM2 gene inhibiting p53

93
Q

how does osteosarcoma spread? imging shows?

A

Spreads via bloodstream to lungs. Mixed osteoblastic or sclerosing (radiodense) and osteolytic (radiolucent) lesion; Codman’s triangle: bone cortex = destroyed –> tumor extends to soft tissue –> lifts periosteum –> periosteum ossifies –> triangle area

94
Q

risk factors of osteosarcoma

A

o Prior radiation or chemotherapy (alkylating agents)
o Paget’s
o Fibrous dysplasia
o Genetics (Li Fraumeni’s)

95
Q

osteochondroma/exostosis

A

most common benign tumor of cartilage-covered bone; Loss of fxn mutation in EXT1 gene encoding enzymes that synthesize heparin sulfate glycosaminoglycans

96
Q

osteochondroma/exostosis consists of? where does it usually occur? what does img show?

A

2 components: Continuous extension cortex and Cartilage cap:
 Nml chondrocytes in lacunae in chondroid matrix
 Outer part of cap has periosteum off underlying bone
 Inner part of cap has stalk made of mature bone.
* Painless palpable mass in metaphyseal regions of long tubular bones
o Knees > humerus.
bony protrusion

97
Q

chondroma. img shows?

A

benign slow growing cartilaginous tumor, can become chondrosarcoma; Mutation in isocitrate dehydrogenase 1&2 (IDH1&2) genes; Oval, central lucent lesion w/ or w/o matrix calcifications

98
Q

periosteal vs endosteal chondroma

A

 From surface of periosteum and grows exophytically
 Long tubular bones –> palpable swelling
vs
 From medullary cavity and grows expansively
 Small bones in hands and feet –> bulbous swelling –> pathologic fx
 Ollier dz and Maffucci Syndrome = nonhereditary dz from enchondromatosis

99
Q

chondrosarcoma

A

malig cartilaginous tumor (low to intermediate/grade 1-2); second most common malig bone tumor; * Mutation in isocitrate dehydrogenase 1&2 (IDH1&2) genes

100
Q

chondrosarcoma pathology vs radiology

A

o Gross: large lobulated mass w/ light blue color in any bone
o Micro: neoplastic cells producing hyaline cartilaginous matrix
vs
o Radiolucency
o Cortical destruction or soft tissue mass

101
Q

EWS

A

3rd most common malig bone tumor; t(11;22)(q24;q12) –> EWS/FLI1 fusion –> dom oncogene –> stimulate cell prolif; Strong CD99 staining

102
Q

EWS imging

A

o Periosteum = lamellated  onion skin appearance
o “Sunburst” pattern
o “Hair-on-end” pattern

103
Q

giant cell tumor of bone

A

benign locally aggressive tumor w/ multinucleated osteoclast-like giant cells; Dark brown soft mass d/t hemorrhage or necrosis –> pain, swelling, dec ROM

104
Q

3 cell types of giant cell tumor of bone. imging?

A

o Mononuclear spindle-shaped cells; Mutation in H3 histone family member 3A (H3F3A) gene encoding histone 3 protein
o Multinucleated giant cells
o Mononuclear histiocytic cells
o img: Lytic lesion in epiphysis and involving metaphysis w/ thin shell

105
Q

aneurysmal bone cyst

A

benign locally aggressive tumor w/ anastomotic cavities containing blood; t(16;17)(q22;q13) in osteoblast cadherin gene CDH11 and USP6 gene –> inc NFkB –> inc matrix metalloprotease –> cystic bone resorption

106
Q

what are Anastomosing channels lined by in aneurysmal bone cysts? img?

A

endothelial cells and have no elastic lamina or muscular layers like true blood vessels. o Sharply defined expansile osteolytic lesion w/ thin sclerotic margins

107
Q

most common sites for bone metastases

A
  • Vertebral body = most common site for metastatic deposit in vertebrae b/c has red bone marrow
  • Skeleton = 3rd most common site for metastases following lung and liver
108
Q

3 types of bone metastases: osteolytic vs osteoblastic vs mixed

A

destruction of nml bone by osteoclasts d/t IL1/6/8/11 and TNFα vs making new bone vs having 2+ types of bone metastases in a single pt

109
Q

bone metastases clinical pres vs lab

A

o Bone pain
o Bone destruction d/t osteolytic metastases –> hypercalcemia
o Spinal cord compress
vs
o High ALP

110
Q

fibromatosis

A
  • Fibroblast prolif
  • Infiltrative growth
  • Variable amt of collagen in b/w prolif cells
  • Lack of cytological features of malignancy
  • Aggressive clinical behavior
111
Q

superficial fibromatosis: palmar vs plantar vs penile

A

Duypuytren’s contracture vs Lederhose dz; nodule in central and medial plantar aponeurosis vs Peyronies; Tunica albuguinea of corpus cavernosum –> abnl penile curvature

112
Q

what causes superficial fibromatosis?

A
  • Immunostaining β-catenin = component of WNT
113
Q

what causes sporadic vs familial desmoid tumor?

A

Mutation in CTNNB1 gene encoding β-catenin –> no β-catenin degradation –> inc β-catenin –> inc WNT pathway –> cell prolif vs Mutation in APC gene –> no β-catenin degradation –> inc β-catenin –> inc WNT pathway –> cell prolif

Block 2 (16 decks)

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