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Musculosceletal system Flashcards

1
Q
  1. Congenital diseases of bone:

DYSTOSES

A
  • developmental abnormalities from problems in migration of mesenchymal cells and formation of condensation
  • single or groups of bones
  • due to mutations of homeobox genes
    ⇒ aplasia
    ⇒ formation of extra bones
    ⇒ abnormal fusion of bones
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2
Q
  1. Congenital diseases of bone:

DYSPLASIAS

A
  • mutation⇒ interfere with bone and cartilage growth + maintenance of normal matrix components
  • more diffuse effects
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3
Q
  1. Congenital diseases of bone:

OSTEOGENESIS IMPERFECTA pathogenesis and morphology

A
  • AD disorder ⇒ defective synthesis of type 1 collagen
    PATHOGENESIS:
  • gene mutation in alpha1 or alpha2 chains of collagen 1 ⇒ premature degradation
    MORPHOLOGY:
  • too little bone ⇒ extreme skeletal fragility
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4
Q
  1. Congenital diseases of bone:

OSTEOGENESIS IMPERFECTA subtypes

A

TYPE 1:
- normal lifespan
- increased proclivity to factors in childhood
- collagen normal but too little produced
TYPE 2:
- fatal pre- or postpartum due to multiple factures in utero
- not enough collagen or bad quality
- respiratory problems
TYPE 3:
- progressive deforming
- enough collagen but deformed
TYPE 4:
- deforming but normal sclera
- not enough collagen nor high enough quality
TYPE 5-7:
- minor subtypes, histological appearances

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5
Q
  1. Congenital diseases of bone:

OSTEOGENESIS IMPERFECTA symptoms

A
  • blue sclera: decreased scleral collagen content ⇒ transparency
  • hearing loss: conduction defect in middle and inner ear bones
  • small misshapen teeth: dentin deficiency
  • no cure
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6
Q
  1. Congenital diseases of bone:

ACHONDROPLASIA pathogenesis

A
  • AD
  • point mutation in FGFR3⇒ constitutive activation
    ⇒ inhibits chondrocyte proliferation ⇒ normal epiphyseal growth plate expansion suppressed + long bone growth stunted
  • problem in endochondral bone formation: proliferation of chondrocytes at cartilage growth plate
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7
Q
  1. Congenital diseases of bone:

ACHONROPLASIA morphology

A
  • affects all bones that form cartilaginous framework
  • marked, disproportionate shortening of proximal extremities, bowing of legs, lordotic posture
  • short stature - dwarfism
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8
Q
  1. Congenital diseases of bone:

THANATOPHORIC DWARFISM

A
  • lethal variant
  • FGFR3 mutation
  • extreme shortening of limbs, frontal blossing of skull, small thorax ⇒ fatal respiratory failure in perinatal period
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9
Q
  1. Congenital diseases of bone:

OSTEOPETROSIS general

A
  • rare genetic disorder ⇒ reduced osteclast-mediated bone resorption ⇒ defective bone remodeling
  • affected bone is grossly dense and stone-like ⇒ fragile + fractures easily
  • AD: mild clinical symptoms
  • AR: severe/lethal
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10
Q
  1. Congenital diseases of bone:

OSTEOPETROSIS pathogenesis + morphology

A

PATHOGENESIS:
- 2 types of defects:
* those that disturb osteoclast function
* those that interfere with osteoclast formation and differentiation
- carbonic anhydrase 2 deficiency ⇒ reduced bone demineralization
MORPHOLOGY:
- primary spongiosa persists
- bone is very thick, stone like

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11
Q
  1. Acquired diseases of bone development:

OSTEOPOROSIS general

A
  • increased porosity of skeleton due to reduced bone mass, associated with increased bone fragility + fractures
  • localized or entire skeleton
    RISK DETERMINATION:
  • based on peak bone mass + amount lost after
  • determined by: diet, exercise, vitamin D receptors
  • estrogen is protective
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12
Q
  1. Acquired diseases of bone development:

OSTEOPOROSIS classification

A

PRIMARY OSTEOPOROSIS:

  1. Senile osteoporosis:
    - areas containing trabecular bone⇒ spine + femoral neck
    - reduced activity of osteoprogenitor cells
    - reduced synthetic activity of osteoblasts
    - reduced biologic activity of matrix bound GF
    - reduced physical activity
  2. Postmenopausal osteoporosis:
    - more bone-loss due to decreased estrogen
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13
Q
  1. Acquired diseases of bone development:

OSTEOPOROSIS morphology

A

BONE LOSS:

  • cortices thinned
  • dilated haversian canal
  • trabeculae lose thickens + interconnections
  • osteoclastic activity a little increased
  • mineral content normal
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14
Q
  1. Acquired diseases of bone development:

OSTEOPOROSIS pathogenesis

A

= dynamic equilibrium between osteoblast, osteocyte and osteoclast activity tilts in favor of resorption
FACTORS:
1. Age related
⇒ osteoblast activity decreases
2. Hormonal changes
⇒ estrogen drop ⇒ increase cytokines ⇒ more RANK-RANKL activity ⇒ less OPG ⇒ increased osteoclast activity
3. Physical activity
⇒ induce bone remodeling
4. Genetic factors
⇒ vitamin D receptor polymorphism in young, calcium uptake, PTH synthesis
5. Calcium nutritional state
6. Secondary causes
⇒ glucocorticoid treatment ⇒ increased resorption + decreased bone synthesis

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15
Q
  1. Acquired diseases of bone development:

OSTEOPOROSIS clinical features

A
  • thoracic and lumbar vertebral fractures ⇒ loss of height and deformities (e.g. kyphoscoliosis)
  • fractures of neck, pelvis, spine ⇒ pulmonary embolism + pneumonia
  • remains asymptomatic until fracture
  • serum Ca, PO4, PTH and APP normal
  • bone density with DEXA scan
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16
Q
  1. Acquired diseases of bone development:

OSTEOPOROSIS treatment

A
  • calcium intake
  • vitamin D supplementation
  • exercise
  • bisphosphonate administration (decrese resorption)
  • estrogen replacement therapy
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17
Q
  1. Acquired diseases of bone development:

RICKETS and OSTEOMALACIA general

A

= vitamin D deficiency or abnormal metabolism
⇒ defective bone mineralization ⇒ overabundant non mineralized osteoid
- affects long bones
RICKETS: childhood disorder, deranged bone growth produce skeletal deformities
OSTEOMALACIA: adult disease, bone formed is under mineralized ⇒ osteopenia + fractures

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18
Q
  1. Acquired diseases of bone development

RICKETS and OSTEOMALACIA pathogenesis

A
  • results from diet deficient in calcium and vitamin D
    CAUSES:
  • limited exposure to sunlight
  • renal disorder ⇒ decreased synthesis of 1,25 OH2D
  • phosphate depletion
  • malabsorption disorders

Vitamin D deficiency ⇒ hypocalcemia ⇒ PTH increased ⇒ activate renal alpha1-hydroxylase
⇒ mobilized calcium from bone
⇒ decrease renal calcium excretion
⇒ increased renal excretion of phosphate

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19
Q
  1. Acquired diseases of bone development

RICKETS and OSTEOMALACIA clinical features

A 
RICKETS:
 - pigeon-breast deformity
 - frontal blossing
 - Rachitic rosary
 - bowing of legs
OSTEOMALACIA:
 - increased risk for fractures (vertebrae + hip)
 - Ca and PO4 decreased, PTH and APP increased
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20
Q
  1. Osteomyelitis, Paget’s disease:

OSTEOMYELITIS general

A

= inflammation of bone and marrow cavity

  • infection⇒acute/chronic/ compilcation of systemic infection
  • usually in children
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21
Q
  1. Osteomyelitis, Paget’s disease:

PYOGENIC OSTEOMYELITIS causes

A

BACTERIA:
- S.aureus
- e.coli, n.gonorrhea, s.agalactiae (neonates)
- salmonella (sickle cell patients)
- pseudomonas (diabetics, IV drug users)
- pasteurella (dog,cat bite patients)
- mycobacterium tuberculosis
- anaerobic (after bone trauma)
PATHWAYS:
1. hematogenous dissemination
2. extension from infection in adjacent joint or soft tissue
3. traumatic implantation/ direct inoculation

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22
Q
  1. Osteomyelitis, Paget’s disease:

PYOGENIC OSTEOMYELITIS morphology

A
  • depend on stage and location
  • bacteria proliferate, induce acute inflammatory reaction + cell death ⇒ early lytic bone necrosis
  • infiltrate throughout haversian system to periosteum
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23
Q
  1. Osteomyelitis, Paget’s disease:

PYOGENIC OSTEOMYELITIS clinical features

A
  • malaise
  • fever
  • leukocytosis
  • throbbing bone pain
    DIAGNOSIS: radiological finding of destructive lytic focus + sclerotic rim // blood culture
    TREATMENT: antibiotics + surgical drainage
    ⇒ can become chronic
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24
Q
  1. Osteomyelitis, Paget’s disease:

TUBERCULOSIS OSTEOMYELITIS

A
  • pathway: hematogenous dissemination or direct spread
  • long bones + vertebrae in the synovium⇒ adjacent epiphysis ⇒ granulomatous inflammation
    POTTS DISEASE:
  • TB in lumbar vertebral bodies
  • cause vertebral deformity and collapse
  • psoas muscle ascesses
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103. Osteomyelitis, Paget's disease: | PAGET DISEASE general
Osteitis deformans 3 STAGES: 1. osteolytic stage ⇒ hyperactive, regional osteoclastic activity + bone resorption 2. mixed osteoclastic-osteoblastic stage ⇒ bone formation 3. osteoscerotic stage ⇒ exhaustion of cellular activity by osteoclasts ⇒ gain in bone mass but disordered and lacks strength - mid/late adulthood
26
103. Osteomyelitis, Paget's disease: | PAGET DISEASE pathogenesis
- Paramyxovirus infection ⇒ induce IL-1 secretion from infected cells - osteoclasts are intrinsically hyper-responsive to vitamin D and RANKL
27
103. Osteomyelitis, Paget's disease: | PAGET DISEASE morphology
- solitary monostotic lesions or in multiple polyostotic sites (but not whole skeleton) 1. initial lytic phase ⇒ numerous osteoclasts + abnormally large (100nuclei) 2. mixed phase ⇒ bone surface lined by osteoblasts, marrow replaced by loose CT 3. sclerotic phase ⇒ periosseous fibrovascular tissue recedes + replaced by marrow (mosaic pattern) ⇒ thickened but cortex soft and prone to deformation and fractures
28
103. Osteomyelitis, Paget's disease: | PAGET DISEASE clinical features
``` SYMPTOMS: - location: axial skeleton and proximal femur (sometimes ribs, fibula, small bones of hands and feet) - bone pain - hearing loss - lion-like face - increased APP TREATMENT: - calcitonin and bisphosponates COMPLICATIONS: - high output cardiac failure - osteosarcoma ```
29
104. Tumors and tumor-like lesions of the bone: | TYPES
1. Bone forming tumors: - Osteoma - Osteoid osteoma - Osteoblastoma - Osteosarcoma 2. Cartilage forming tumors: - Osteochondroma - Chondroma - Chondrosarcoma 3. Fibrous and fibro-osseous tumors: - Fibrous cortical defect - Fibrous dysplasia 4. Other tumors: - Ewing sarcoma - Giant cell tumor
30
104. Tumors and tumor-like lesions of the bone: | OSTEOMA
- benign - reactive growths or developmental abnormalities - usually surface of facial bones - middle age - solitary, localized, slowly growing, hard, exophytic masses - multiple lesions ⇒ Gardner syndrome - Histo: mix of woven and lamellar bone - local mechanical problem or cosmetic deformity
31
104. Tumors and tumor-like lesions of the bone: | OSTEOID OSTEOMA
- benign neoplasm - made of osteoblasts (osteoid+ rim of sclerotic bone) - young adults, male predominance (2:1) Location: cortex of long bones - diaphysis Morphology: well circumscribed, hemorrhagic gritty tan, rim of sclerotic tissue, nidus centrally, <2cm Symptoms: localized pain Treatment: aspirin + local excision
32
104. Tumors and tumor-like lesions of the bone: | OSTEOBLASTOMA
- benign neoplasm - made of osteoblasts (osteoid+rim of sclerotic bone) Location: vertebral column Morphology: well-circumscribed, hemorrhagic gritty tan, rim of sclerotic tissue, nidus centrally, >2cm Symptom: pain, but difficult to localize Treatment: local excision
33
104. Tumors and tumor-like lesions of the bone: | OSTEOSARCOMA
- bone-producing malignant tumor, proliferation of osteoblasts Age: <20years + elderly Predominance: male PATHOGENESIS: - RB gene mutation - p53, cyclin, CDK, kinase inhibitor mutation - Li Fraumeni MORPHOLOGY: - location: metaphysis of long bones of extremities - grey-white tumor, infiltrate surrounding cortex - symptoms: fractures, bone pain, swelling - Codman's triangle: triangular shadow between cortex + raised periosteum - hematogenous spread ⇒ lungs TREATMENT: chemotherapy + surgery (5 year survival- 70%)
34
104. Tumors and tumor-like lesions of the bone: | OSTEOCHONDROMA
``` - benign cartilage-covered outgrowths attached by bony stalk to skeleton TYPES: - solitary (adulthood) - multiple (childhood) PATHOGENESIS: - inactivation of EXT gene Location: bones of endochondral origin - metaphysis - lateral projection of growth plate ```
35
104. Tumors and tumor-like lesions of the bone: | CHONDROMA
- benign tumors of hyaline cartilage Locations: small bones of hand and feet Types: - Enchondroma (medulla) - Juxtacortical (bone surface) Ollier disease: multiple chondromas on 1 side of body Maffucci syndrome: multiple chondromas associated with benign soft tissue angiomas
36
104. Tumors and tumor-like lesions of the bone: | CHONDROSARCOMA
``` - malignant tumor producing cartilage Location: pelvis + central skeleton CLINICAL FEATURES: - painful, progressively enlarging mass - >10cm tumors more aggressive - metastasize hematogenously ⇒ lungs + skeleton TREATMENT: - surgical excision - chemotherapy ```
37
104. Tumors and tumor-like lesions of the bone: | FIBROUS CORTICAL DEFECT
- benign developmental defect Age: children >2 years MORPHOLOGY: - grey-yellow-brown lesion - <0,5cm - metaphysis of distal femur and proximal tibia - Histo: cellular lesion + cytologically benign fibroblasts + activated macrophages CLINICAL FEATURES: - may undergo spontaneous differentiation into normal cortical bone - few enlarge ⇒ pathologic fracture
38
104. Tumors and tumor-like lesions of the bone: | FIBROUS DYSPLASIA
- bening tumor with localized developmental arrest 1. MONOSTOTIC: - begins in early adolescence, ceases with epiphyseal closure - location: ribs, femur, tibia, jawbones, calvaria, humerus - asymptomatic - enlargement and distortion of bone 2. POLYOSTOTIC: - earlier age and progress into adulthood - location: femur, skull, tibia, humerus - craniofacial involvement - involve pelvic and shoulder gridles 3. POLYOSTOTIC DISEASE: - cafe au lait skin pigmentation + endocrine abnormalities - early age puberty - somatic embryonic mutation ⇒ G-protein always active
39
104. Tumors and tumor-like lesions of the bone: | EWING SARCOMA + PRIMITIVE NEUROECTODERMAL TUMOR general + morphology
- malignant tumors - arise from neuroectoderm - male children MORPHOLOGY: - medullary cavity of diaphysis of long bones ⇒ onion-skin-like layering - white tumor, hemorrhage + necrosis - Homer-wright rosettes - PNETs ⇒ differentiated, Ewing ⇒ undifferentiated
40
104. Tumors and tumor-like lesions of the bone: | EWING SARCOMA + PRIMITIVE NEUROECTODERMAL TUMOR pathogenesis
Translocation ⇒ fusion of EWS gene with ETS family of transcription factors ⇒ t(11;22) FL1-ERG ⇒ cMYC promoter
41
104. Tumors and tumor-like lesions of the bone: | GIANT CELL TUMOR
- arise from multinucleate giant cells + stromal cells - occurs in young adults - arises in epiphysis of long bones - soap-bubble appearance on x-ray - locally aggressive
42
104. Tumors and tumor-like lesions of the bone: | METASTASIS TO THE BONE
ADULTS: - prostate, breast, kidney, lung, thyroid CHILDREN: - neuroblastoma, Wilm's tumor, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma ⇒ most involve axial skeleton , proximal femur, humerus
43
105. Degenerative and inflammatory joint diseases: | OSTEOARTHRITIS general + classification
``` - degenerative disorder of articular cartilage ⇒ physical disability in people >65 y Risk factors: age, obesity, trauma CLASSIFICATION: 1. Primary OA: - due to aging - oligoarticular 2. Secondary OA: - youth with predisposing factors (injury, developmental deformity, systemic disease) - one or several joints - women: hands + knees - men: hips ```
44
105. Degenerative and inflammatory joint diseases: | OSTEOARTHRITIS morphology
EARLY CHANGES: - superficial layers degraded ⇒ fibrillation + cracking of matrix - histo: chondromalacia + chondrocyte apoptosis - more water + less proteoglycan - tensile strengt + resilience compromised LATE CHANGES: - bone eburnation⇒ exposed bone plate polished by friction⇒ osteophytes - cysts inside bone - pannus formation
45
105. Degenerative and inflammatory joint diseases: | OSTEOARTHRITIS clinical features
Age: 50s-60s Location: hip, lower lumbar spine, knees, DIP, PIP Symptoms: pain intensified by daily use, morning stiffness, crepitus + limited range of movement - impingement of spinal foramen ⇒ nerve root compression ⇒ radicular pain, muscle spasm, muscle atrophy, neurological deficits - Heberden nodes
46
105. Degenerative and inflammatory joint diseases: | RHEUMATOID ARTHRITIS
- systemic, chronic inflammatory disease - autoimmune disease * Cyclic citrullinated peptide autoantibodies * Rheumatoid factor - middle aged women - associated with HLA-DR4 mutations - causes nonsuppurative proliferative synovitis ⇒ pannus - affects small joints - rheumatoid subcutaneous nodules - morning stiffness
47
105. Degenerative and inflammatory joint diseases: | SUPPURATIVE ARTHRITIS
- Bacteremia * H.influenzae (<2years) * Gonococcus (late adolescence, young adulthood) * S.aureus (older children, adults) - sudden onset of pain, redness and swelling of joint + restricted range of motion - fever, leukocytosis, elevated ESR
48
105. Degenerative and inflammatory joint diseases: | LYME ARTHRITIS
``` CAUSE: Borrelia burgdorferi STAGE 1: - bacteria multiply at site of bite ⇒ area of redness STAGE 2: - hematogenous spread ⇒ skin lesions, lymphadenopathy, migratory joint + muscle pain, cardiac arrhythmia, meningitis STAGE 3: - 2-3 years later - chronic arthritis, encephalitis ```
49
105. Degenerative and inflammatory joint diseases: | GOUT
- more in males, >30 years old - cause: excessive uric acid - characteristics: recurrent acute arthritis ⇒ permanent joint deformity - risk factors: alcohol, red meat, obesity, metabolic syndrome, renal failure - types: primary/secondary PATHOGENESIS: - URAT1 and GLUT9 mutations MIRPHOLOGY: - acute arthritis - trophi ⇒ ureate crystals surrounded by inflammatory cells - nephropathy
50
105. Degenerative inflammatory joint diseases: | STAGES OF GOUT
STAGES: 1. Asymptomatic hyperuricemia (puberty in men, menopaus in women) 2. Acute gouty arthritis ⇒ pain, erythema, warmth 3. Intercritical gout 4. Chronic tophaceous gout ⇒ erosion of juxta-articular bone by crystals + loss of joint space
51
105. Degenerative and inflammatory joint diseases: | PSEUDOGOUT
- calcium pyrophosphate crystal deposition - age 50 - accumulation of pyrophosphate ⇒ crystallization ⇒ inflammation ⇒ joint damage - hereditary form: crystals from early / osteoarthritis - no treatment
52
106. Muscular atrophy, dystrophies and myositis: | TYPES
``` PRIMARY MYOPATHIES: ⇒ disorder of muscle, myopathic 1. muscular atrophy 2. genetic disorders: - muscular dystrophies - congenital muscular dystrophies - congenital myopathies SECONDARY MYOPATHIES: ⇒ disorder that disrupt muscle innervation, neuropathic 1. muscular atrophy 2. myastenia gravis ```
53
106. Muscular atrophy, dystrophies and myositis: | MYASTENIA GRAVIS
- autoimmune disease - target: Acetylcholine receptors of NMJ Symptoms: * double vision * droopy eyelids * difficulty swallowing * weakness Treatment: anti-Ach agents - associated with thymic hyperplasia or thyoma
54
106. Muscular atrophy, dystrophies and myositis: | MUSCULAR ATROPHY etiology
⇒ abnormally small myofibers 1. Neuropathic atrophy - due to loss of innervation - involves both fiber types and by clustering of myofibers into small groups 2. Atrophy as result of disease - prolonged immobilization - primary affects type 2 fibers⇒ random distribution 3. Glucocorticoids - cushing syndrome - affects type 2 fibers + mostly proximal muscle ⇒ random distribution 4. Endogenous hypercortisolism - affects type 2 fibers ⇒ random distribution 5. Myopathy atrophy - additional morphologic changes like myofiber degeneration + regeneration, chronic remodeling or inflammatory infiltrate
55
106. Muscular atrophy, dystrophies and myositis: | MUSCULAR DYSTROPHY general
- inherited disorders, presenting in childhood - progressive degeneration of muscle fibers ⇒ muscle weakness + wasting - muscle fibers replaced by fibrofatty tissue SUBTYPES: - Duchenne-Becker muscular dystrophy - Autosomal muscular dystrophies - Myotonic dystrophy
56
106. Muscular atrophy, dystrophies and myositis: | DUCHENNE AND BECKER MUSCULAR DYSTROPHY general
``` - X-linked disorder DMD: - most severe - 1/3500 male - clinically evident by age 5 ⇒ progressive weakness⇒ death by early 20s BMD: - less common, less severe ```
57
106. Muscular atrophy, dystrophies and myositis: | DUCHENNE AND BECKER MUSCULAR DYSTROPHY pathogenesis
- 2/3 of cases familial - deletion/ abnormalities in dystrophin gene (Xp21) - dystrophin expressed in muscles, brain, peripheral nerves - dystrophin attached sarcomere to cell membrane + transfers force of contraction to CT DMD: no dystrophin BMD: low amount of abnormal dystrophin
58
106. Muscular atrophy, dystrophies and myositis: | DUCHENNE AND BECKER MUSCULAR DYSTROPHY clinical features
``` DMD: - clumsiness + pseudo hypertrophy of calf muscles - cardiac muscle fibrosis ⇒ failure - proximal muscle weakness- 1 years old - elevated creatine kinase BMD: - symptoms later in childhood - progresses slower ```
59
106. Muscular atrophy, dystrophies and myositis: | AUTOSOMAL MUSCULAR DYSTROPHIES
LIMB GIRDLE MUSCULAR DYSTROPHIES: - AD or AR - proximal musculature of trunk and limbs EMERY-DREIFUS MUSCULAR DYSTROPHY: - mutation in structural proteins in nucleus: repeated mechanical stress of defected genes ⇒ loss of structural integrity
60
106. Muscular atrophy, dystrophies and myositis: | MYOTONIC DYSTROPHY
Myotonia: sustained involuntary contraction of a group of muscles Symptoms: - stiffness - gait abnormalities - weakness of intrinsic muscles of hands and wrist extensors - atrophy of facial muscles with ptosis Pathogenesis: - inherited as AD - CTG trinucleotide repeat on chromosome 19 ⇒ DMPK ⇒ concentration of protein product - increase in severity + appear at younger age in next generations
61
106. Muscular atrophy, dystrophies and myositis: | POLYMYOSITIS
- Autoimmune disorder ⇒ increase expression of MHC 1 on myofibers - CD8+ T cell infiltrates - autoimmune attack ⇒ myofiber necrosis ⇒ regeneration Treatment: corticosteroids, immunosuppressants
62
106. Muscular atrophy, dystrophies and myositis: | DERMATOMYOSITIS
- mostly in children - in adults ⇒ paraneoplastic disease - inflammation of muscle + skin - histo: perivascular mononuclear cell infiltrates, drop-out of capillary, tubuloreticular inclusions in endothelial cells + myofiber damage - IFN upregulated
63
106. Muscular atrophy, dystrophies and myositis: | INCLUSION BODY MYOSITIS
- patients over 60 years old | - presence of rimmed vacuoles with protein aggregates
64
107. Tumors of joints and the muscles: | TYPES OF JOINT TUMORS
1. Neoplasms of synovium - TGCT 2. Neoplasms of vessels - hemangioma - angiosarcoma 3. Neoplasms of fibrous tissue - fibrosarcoma 4. Neoplasms of cartilage - chondroma - chondrosarcoma
65
107. Tumors of joints and the muscles: | TENOSYNOVIAL GIANT CELL TUMOR general
- closely-related benign neoplasms Types: - Pigmented villonodular synovitis PVNS ⇒ involve joints diffusely - Giant cell tumor of tendon sheath GCT ⇒ single tendon sheath nodule Age: 20-40s - translocation t(1;2) fuses promoter of collagen gA3 gene to growth factor M-CSF
66
107. Tumors of joints and the muscles: | TENOSYNOVIAL GIANT CELL TUMOR morphology
- red-brown/ orange-yellow masses - tumor cells look like synoviocytes - hemosiderin-laden macrophages, osteoclast-like giant cells + hyalinized stromal collagen PVNS: - monoarticular arthritis ⇒ knee, hip, ankle - pain, locking + recurrent swelling GCT: - solitary, slow-growing, painless mass - wrist and finger tendon sheath
67
107. Tumors of joints and the muscles: | SYNOVIAL SARCOMA general
- doesn't originate from synovicytes - age: 20-40s - develop in deep of tissues around large joints of extremities - t(X;18) translocation ⇒ fusion SYT gene with SSX1 or SSX2 genes
68
107. Tumors of joints and the muscles: | SYNOVIAL SARCOMA morphology
Biphasic: - epitheloid cells: cuboidal-columnar, form glands or grow in solid cords - spindle cells: dense cellular fascicles surrounding epithelial cells Monophasic: - only spindle cells TREATMENT: surgery, chemotherapy METASTASIS: lung, bone, LN
69
107. Tumors of joints and the muscles: | FIBROSARCOMA
- malignant neoplasms - composed of fibroblasts - occurs in adults - deep tissues of thigh, knee, retroperitoneal area - grow slowly - reoccur after excision - metastasis to lungs MORPHOLOGY: - soft, unencapsulated, infiltrative - hemorrhage + necrosis
70
107. Tumors of joints and the muscles: | GANGLION CYST
- small cysts, near joint capsule or tendon sheath - firm- fluctuate pea-sized nodules - arise by cystic degeneration of CT - Histo: fluid-filled space without true cell lining - completely asymptomatic
71
107. Tumors of joints and the muscles: | SYNOVIAL CYST
- herniation of synovium through joint capsule or massive enlargement of bursa - Baker cyst in popliteal fossa (associated with rheumatoid arthritis)
72
107. Tumors of joints and the muscles: | LEIOMYOMA
- benign - well-circumscribed neoplasm - arise anywhere in the body from smooth muscle - most commonly in uterus + skin
73
107. Tumors of joints and the muscles: | LEIOMYOSARCOMA
- malignant smooth muscle tumor - in adults, more in females - usually in skin, deep soft tissues of extremities and retroperitoneum - firm, painless mass - Histo: spindle cells with cigar shaped nuclei arranged in interweaving fascicles
74
107. Tumors of joints and the muscles: | RHABDOMYOMA
``` -benign tumor of skeletal muscle Location: - adult: oral cavity - fetal: head, neck, heart - genital: vulvologenital - cardiac rhabdomyoma ⇒ associated with tuberous sclerosis (hamartoma) ```
75
107. Tumors of joints and the muscles: | RHABDOMYOSARCOMA general
- malignant tumor of skeletal muscle - age: usually before 20s - location: head, neck, genitourinary tract PATHOGENESIS: - chromosomal translocation t(2;13) fuses PAX3 with FKHR
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107. Tumors of joints and the muscles: | RHABDOMYOSARCOMA morphology
1. Embryonal ⇒ soft, gelatinous, grape-like mass 2. Alveolar - more aggressive 3. Pleomorphic - rhabdomyoblast - desmin positive (Ted-Pole cell) TREATMENT: - surgery, chemotherapy, radiation

PATHOLOGY 2 (11 decks)

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