Bone Path And Soft Tissues

Front 1

Back 1

osteoporosis

Hint 1

Metabolic bone disease, decrease bone mass, 8F>1M, more whites
Same osteoid: mineralized bone but thinner cortex and less coarse cancellous bone trabeculae. Seen most in cancellous bone (vertebrae), causes wedging and collapse.
Type 1: disruption in connections between trabeculae → fx. Post-menopausal women, increase in osteoclastic activity due to estrogen withdrawal → IL-1, Il-6, TNF, MCSF)
Type 2 (senile osteoporosis): fewer trabecular bone, attenuated osteoblastic function can’t keep up with osteoclasts.
Factors: genetics (bone mass, BMD), calcium intake, calcium absorption and vitamin D (less 1 alpha hydroxylase activity, decreased kidney response to PTH), exercise, cigarettes (decreased estrogen)

Front 2

Back 2

osteogenesis imperfecta

Hint 2

AD, type 1 collagen (chr 7 and 17), 4 types. Affects skeleton, joints, ears, ligaments, teeth, sclerae, skin
Rad: osteopenia, variable deformity.
Histo: disorganized growth plate, no trabecular pattern, numbreous plump osteocytes and prominent osteoid seams

OI 1: mildest (AD), fx as toddler, blue sclera, hearing and teeth abnormality, flat feet, kyphoscoliosis
Histo: thing bones, exuberant callus formation.
OI 2: lethal, prenatal (AD)
OI 3: progressive, many bone fxs, growth retardation, severe skeletal abn. Sclerae become white. Teeth abn.
OI 4: like type 1 but with normal sclerae, cortical bone: woven bone with some lamellar bone, fractures (treat aggressively to allow growth)

Front 3

Back 3

multiple endchondromatosis

Front 4

Back 4

osteonecrosis

Hint 4

death of bone and marrow in the absence of infection: caused by trauma, emboli, steroids, radiation, organ transplantation<br>Histo: cancellous bone is replaced by creeping substitution, creeping neovascular tissue replaces marrow. cortical bone is replaced by cutting cones (along preexisting channels), osteoclasts and osteoblasts enter to make new bone.<br>Rad: dense due to osteoporosis in surrounding bone compared to necrotic bone, addition of new bone (creeping substitution), formation of calcium soaps, compaction of necrotic bone

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Back 5

reactive bone formation

Front 6

Back 6

myositis ossificans circumscripta

Front 7

Back 7

chronic osteomyelitis

Hint 7

inflammation of the bone and bone marrow, usually bacterial (Staph, also E. coli, N. gonorrhea, H. flu, Salmonella).
Direct penetration: bacteria enter via wounds, fractures, surgical procedures
Hematogenous: from blood stream, boys 5-15yo, drug addicts.
Open growth plate → vascular loop system → slow blood allows bacteria to get in → proliferation → pressure on bone → bone resorption
If not contained, pus and bacteria can enter cortex and periosteum, shear off parosteal blood vessels and even eventually involve the joint.
Chronic: lymphocytes and plasma cells, marrow fibrosis
Comps: septicemia, acute bacterial arthritis, pathologic fx, chronic osteomyelitis, SCC, amyloidosis.

Front 8

Back 8

TB

Front 9

Back 9

congenital syphillis

Front 10

Back 10

eosinophillic granuloma

Front 11

Back 11

osteoporosis

Hint 11

Metabolic bone disease, decrease bone mass, 8F>1M, more whites
Same osteoid: mineralized bone but thinner cortex and less coarse cancellous bone trabeculae. Seen most in cancellous bone (vertebrae), causes wedging and collapse.
Type 1: disruption in connections between trabeculae → fx. Post-menopausal women, increase in osteoclastic activity due to estrogen withdrawal → IL-1, Il-6, TNF, MCSF)
Type 2 (senile osteoporosis): fewer trabecular bone, attenuated osteoblastic function can’t keep up with osteoclasts.
Factors: genetics (bone mass, BMD), calcium intake, calcium absorption and vitamin D (less 1 alpha hydroxylase activity, decreased kidney response to PTH), exercise, cigarettes (decreased estrogen)

Front 12

Back 12

osteomalacia

Hint 12

Metabolic bone disease
Osteomalacia: adults, inadequate mineralization of newly formed bone matrix
Rickets: kids, extensive changes within the growth plate (prolif and calcified cartilage zones continue to grow, becomes lobulated and irregular with endochondral calcification. Assoc with abnormal vit D, phosphate deficiency, defects in mineralization.
Rad: osteopenia, compression fractures, Pseudofractures of Milkman-Looser (radiolucent, transverse defects, no associated callus formation)
Histo: exaggeration of osteoid seams in thicenss and proportion of trabecular surface covered.
Clin: muscle weakness, difuse aches and pain, or poorly localized bone pain and tenderness. Kids: apathetic, irritable, short attention span, bad bones and teeth, frontal bossing, rachitis rosary, pectus carinatum.

Front 13

Back 13

primary hyperparathyroid

Hint 13

Metabolic bone disease
PTH → increased resorption by accelerated remodeling.
90% due to adenomas, 10% due to 4gland hyperplasias.
3 stages: early (osteoclast stimulation, cutting cones, peritrabecular fibrosis), Osteitis fibrosa (loose marrow fibrosis, hemosiderin-laden macrophages, hemorrhage from microfx and reactive woven bone), osteitis fibrosa cystica (cystic degeneration, gian cells, reactive bone, hemosiderin-laden macrophages.
“Brown tumors” : can look like giant cell tumors, check PTH!

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Back 14

primary hyperparathyroid

Hint 14

Metabolic bone disease
PTH → increased resorption by accelerated remodeling.
90% due to adenomas, 10% due to 4gland hyperplasias.
3 stages: early (osteoclast stimulation, cutting cones, peritrabecular fibrosis), Osteitis fibrosa (loose marrow fibrosis, hemosiderin-laden macrophages, hemorrhage from microfx and reactive woven bone), osteitis fibrosa cystica (cystic degeneration, gian cells, reactive bone, hemosiderin-laden macrophages.
“Brown tumors” : can look like giant cell tumors, check PTH!

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Back 15

renal osteodystrophy

Hint 15

fibrosis on A, osteomalacia on B and adynamic bone disease on C

Front 16

Back 16

Paget's dz

Hint 16

Disordered bone remodeling. >60yo, only one or a few bones. Hereditary and viral origins proposed.
Histo: 3 stages: hot (osteoclastic resorptive stage) (lytic lesions in the cortex, osteolysis, mild fibrosis, dilated marrow sinusoids). Mixed stage (osteblasts and osteoclasts, thickened cortical and cancellous bone, abundant but haphazard cellular activity). Cold (burnt out) stage (little cellular activity, disordered thickened bones, osteoclasts with >100 nuclei (killer clasts), prominent mosaic pattern of trabecular bone with paratrabecular fibrosis.
Clin: Pain, axial>appendicular, skull , pagetic steal (light-headedness due to increased blood demand), fx, arthritis, high-output cardiac failure, sarcomatous change (<1%), severe disease. Increased Alk Phos.
Most pts asx and require no treatment. Calcitonin, bisphosphonates, mithramycin can be used.

Front 17

Back 17

Paget's Dz

Hint 17

Disordered bone remodeling. >60yo, only one or a few bones. Hereditary and viral origins proposed.
Histo: 3 stages: hot (osteoclastic resorptive stage) (lytic lesions in the cortex, osteolysis, mild fibrosis, dilated marrow sinusoids). Mixed stage (osteblasts and osteoclasts, thickened cortical and cancellous bone, abundant but haphazard cellular activity). Cold (burnt out) stage (little cellular activity, disordered thickened bones, osteoclasts with >100 nuclei (killer clasts), prominent mosaic pattern of trabecular bone with paratrabecular fibrosis.
Clin: Pain, axial>appendicular, skull , pagetic steal (light-headedness due to increased blood demand), fx, arthritis, high-output cardiac failure, sarcomatous change (<1%), severe disease. Increased Alk Phos.
Most pts asx and require no treatment. Calcitonin, bisphosphonates, mithramycin can be used.

Front 18

Back 18

fibrous dysplasia

Hint 18

Developmental disorder, fibrous and osseous elements<br>Rad: ground glass lesions, well-marginated<br>Monostotic or Polyostotic. May be quiescent at puberty, may be stimulated by pregnancy.
Tx: Repair of fractures.
Pathogenesis: increased cAMP from genetic mutations
Histo: benign fibroblastic tissue in loose whorled pattern, irregular spicules, no osteoblastic rims. 10% have islands of cartilage, can have cystic degeneration with hemosiderin-laden macrophages, hemorrhage, osteoclasts

Front 19

Back 19

solitary bone cyst

Hint 19

benign, fluid-filled, unlilocular lesions
M>F
Metaphyseal, by growth plate, proximal humerus/femur
Disturbed bone growth by trauma, maybe due to hematoma, pressure → resorption of bone. Slow process.
Rad: well-marginated radiolucent (lytic) lesion
Histo: thing fibrous tissue, few giant cells and hemosiderin-laden macrophages, chronic inflammatory cells, reactive bone lining cyst. Osteoclasts on advancing edge. Proteinaceous material in cysts.

Front 20

Back 20

aneurysmal bone cyst

Hint 20

uncommon, hyperemic, children and young adults, history of trauma
long bones and vertebrae
rad: lytic lesions on x-ray, fluid-fluid levels on MRI
rupture and hemorrhage is possible
gross: ballooned periosteum (blood-filled sponge)
histo: granulation tissue, scattered multinucleated giant cells, osteoid trabeculae

Front 21

Back 21

osteoid osteoma

Hint 21

small painful lesion of osseous tissue (nidus) surrounded by halo of reacive bone formation
5-25yo
diaphysis, cortex of long bones, esp lower limbs
clin: pain (nocturnal, worse with EtOH, better with aspirin)
rad: sclerotic ortical based lesion with central nidus, <1cm
gross: spherical, hyperemic, soft. Soaks up tetracycline
histo: cellular, granulation tissue, osteoblasts, osteoclasts, thing trabecular bone more mature at the center with sclerotic reactive bone around
tx: curettage, elcrocautery, radio frequency ablation, mini-bloc excision

Front 22

Back 22

chondroblastoma

Hint 22

uncommon, benign. Epiphyseal of tubber femur, tibia and humerus
5-25yo, M>F
moderate pain, larger lesions can destroy the bone
rad: eccentric, radiolucent lesion, sharp borders. Mottled matrix on CT
goss: soft, compact, scattered gray or hemorrhagic area.
Histo: primite chondroblasts arranged in sheet of round/polyhedral cells with grooved nuclei. Calcification, multinucleated giant cells.
Tx: curettage, 10% recur.

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Back 23

osteosarcoma

Hint 23

most common primary bone tumor
10-20yo, M>F, knee or shoulder, metaphyseal. Older ppl, it’s due to Paget or radiation.
RB and p53 mutations
Clin: mild/intermittent pain, swelling, tenderness, increased serum Alk Phos
Rad: lytic lesions, periosteum with rim of reactive bone (Codman’s triangle (uplifted periosteum), sunburst pattern)
Gross: variable
Histo: malignant osteoblasts produce woven bone, haphazard, foci of malignant cartilage, pleomorphic giant cells. Atypical mitotic figures.
Tx: adjuvant therapy, limb sparing surgery. 85% 5yr survival. Mets to lungs, also to bones, pleura, heart.

Front 24

Back 24

giant cell tumor

Hint 24

locally aggressive, can be malignant, more in Asian countries, F>M, microfx.
rad: between metaphysis and epiphysis of long bones. Lytic lesion with little periosteal reaction. Thin bony shell, may extend into bone. Soap bubble.
Gross: hemorrhagic area, blood-filled sponge
histo: Mononuclear stroma (plump, large nucleus, mitoses), large osteoclastic multinucleated cells (random distribution). Rich vascularized stroma.
Tx: curettage, bone grafting, mets to lungs (5-10%)

Front 25

Back 25

ewing sarcoma

Hint 25

uncommon, malignant, M>F, rare in AA, small round cells
from primitive marrow elements , t(11;22) (worse prog)
May have fever and weakness, bone pain
rad: midshaft/diaphysis, onion-skin pattern (periosteal new bone reaction to keep in check).
Gross: soft and grayish, hemorrhage and focal necrosis, soft tissue expansion
Histo: sheets of packed small round cells, irregular nests of cells, little/no interstitial stroma, PAS positive, CD99 positive
Tx: chemo, radiation, surgery. 60-75% 5yr survival

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Back 26

multiple myeloma

Hint 26

malignant plasma cell tumor, older people, M>F
rad: lytic due to cytokines, especially skull, spine, ribs, pelvis, femur
histo: sheets of plasma cells with varying maturity, amyloid in 10%, SPEP for monoclonal process
tx: chemotherapy, radiation
cause of death: kidney failure

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Back 27

metastatic carcinoma

Hint 27

most common malignant bone tumor
breast, prostate, lung, thyroid, kidney. Vertebral column is the most common.
thyroid, kidney, neuroblastoma and GI are lytic; prostate, breast, lung and stomach are blastic. Usually have a mix of lytic and blastic

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Back 28

articular hyaline cartilage

Front 29

Back 29

ankylosing spondylitis

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Back 30

CPPD

Front 31

Back 31

pigmented villonodular synovitis

Back 32

nodular fasciitis

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Back 33

nodular fasciitis

Hint 33

benign, rapidly-growing, from trauma.
Supl tissues of forearm, trunk, and back, usually in adults on extensor surfaces.
Histo: cellular mitotically active lesion with pleomarphic spindle cells. Exuberant granulation tissue.
Tx: excision

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Back 34

fibrosarcoma

Hint 34

malignant tumor of fibrobalsts, usually I thigh, adult, any age.
Congenital: t(12;15)
Gross: firm, sharply demarcated, necrosis and hemorrhage
Histo: pleomorphic fibroblasts in dense interlacing bundles and fascicles (herringbone pattern).
Bad prognosis

Back 35

pleomorphic spindle cell sarcoma

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Back 36

liposarcoma

Hint 36

malignant, second most common
50yo, deep thigh, retroperitoneum, slow-growing. Myxoid variant: t(12;16)
gross: 5-10cm, may have necrosis, cysts, hemorrhage
histo: lipoblasts (signet ring) in a vascularized myxoid stroma
tx: prog depends on differentiation

Front 37

Back 37

rhabdomyosarcoma

Hint 37

children and young adults, from primitive mesenchyme
embryonal rhabdomyosarcoma: most common type, 3-12yo, usually head and neck.
Immunohistochemical stains make the diagnosis. Molecular studies for alveolar type: t(2;13) (bad prognosis). Botryoid and pleomorphic types also exist.
Tx: surgery, chemo, radiation.

Front 38

Back 38

synovial sarcoma

Hint 38

highly malignant, comes from tendon sheaths, bursa in joint capsules, <10% interarticular.
Adolescants and young adults in large joints.
T(x;18)
Gross: circumscribed, round or multilobular mass. Pseudocapsule, cystic changes.
Histo: spindle cell and epithelia-like area. Monophasic (spindled) variant also exists. Immunohistochemical stains for epithelial differentiation
Tx: high recurrence, mets in >60%, 50% to lung mets.

Front 39

Osteopetrosis

Back 39

inheritable; abnormally dense bone
mortality from anemia, CN entrapment, hydrocephalus, infection (AR)
AD: more benign, no sxs.
Decreased osteoclast function (TRIRG1 gene, carbonic anhydrase gene)
x-ray: short opaque bones
clin: bone weakness, fractures, anemia, hypopenia, deafness, blindness
gross: erlenmeyer flask bone, thickened cortex, no metaphyseal funnelization
histo: irregular bone tissue with cartilage, osteoclasts increased, decreased or normal.
tx: bone-marrow transplant

Front 40

Back 40

Osteogenesis imperfecta

Hint 40

AD, type 1 collagen (chr 7 and 17), 4 types. Affects skeleton, joints, ears, ligaments, teeth, sclerae, skin
Rad: osteopenia, variable deformity.
Histo: disorganized growth plate, no trabecular pattern, numbreous plump osteocytes and prominent osteoid seams

OI 1: mildest (AD), fx as toddler, blue sclera, hearing and teeth abnormality, flat feet, kyphoscoliosis
Histo: thing bones, exuberant callus formation.
OI 2: lethal, prenatal (AD)
OI 3: progressive, many bone fxs, growth retardation, severe skeletal abn. Sclerae become white. Teeth abn.
OI 4: like type 1 but with normal sclerae, cortical bone: woven bone with some lamellar bone, fractures (treat aggressively to allow growth)

Front 41

Back 41

Osteonecrosis

Hint 41

death of bone and marrow in the absence of infection: caused by trauma, emboli, steroids, radiation, organ transplantation

Legg-Calve-Perthes disease: focal bone necrosis involving the femoral head in children→ stress fxs, compaction, neovascularization, subchondral cracking → collapse of subchondral bone → severe arthritis
Due to open growth plate in kids that don’t allow blood vessels through → fed by blood vessels around neck, susceptible to trauma and compression
Histo: cancellous bone is replaced by creeping substitution, creeping neovascular tissue replaces marrow. cortical bone is replaced by cutting cones (along preexisting channels), osteoclasts and osteoblasts enter to make new bone.
Rad: dense due to osteoporosis in surrounding bone compared to necrotic bone, addition of new bone (creeping substitution), formation of calcium soaps, compaction of necrotic bone.

Front 42

Back 42

Osteomyelitis

Hint 42

inflammation of the bone and bone marrow, usually bacterial (Staph, also E. coli, N. gonorrhea, H. flu, Salmonella).
Direct penetration: bacteria enter via wounds, fractures, surgical procedures
Hematogenous: from blood stream, boys 5-15yo, drug addicts.
Open growth plate → vascular loop system → slow blood allows bacteria to get in → proliferation → pressure on bone → bone resorption
If not contained, pus and bacteria can enter cortex and periosteum, shear off parosteal blood vessels and even eventually involve the joint.
Open sinus tract can go to skin

Front 43

Back 43

Osteomyelitis

Hint 43

inflammation of the bone and bone marrow, usually bacterial (Staph, also E. coli, N. gonorrhea, H. flu, Salmonella).
Direct penetration: bacteria enter via wounds, fractures, surgical procedures
Hematogenous: from blood stream, boys 5-15yo, drug addicts.
Open growth plate → vascular loop system → slow blood allows bacteria to get in → proliferation → pressure on bone → bone resorption
If not contained, pus and bacteria can enter cortex and periosteum, shear off parosteal blood vessels and even eventually involve the joint.
Open sinus tract can go to skin

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Back 44

Acute osteomyelitis

Hint 44

PMN infiltrate, nonviable trabecular bone and marrow

Comps: septicemia, acute bacterial arthritis, pathologic fx, chronic osteomyelitis, SCC, amyloidosis.

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Back 45

Chronic osteomyelitis

Hint 45

lymphocytes and plasma cells, marrow fibrosis
Comps: septicemia, acute bacterial arthritis, pathologic fx, chronic osteomyelitis, SCC, amyloidosis.

Front 46

Back 46

Osteoporosis

Hint 46

Metabolic bone disease, decrease bone mass, 8F>1M, more whites
Same osteoid: mineralized bone but thinner cortex and less coarse cancellous bone trabeculae. Seen most in cancellous bone (vertebrae), causes wedging and collapse.
Type 1: disruption in connections between trabeculae → fx. Post-menopausal women, increase in osteoclastic activity due to estrogen withdrawal → IL-1, Il-6, TNF, MCSF)
Type 2 (senile osteoporosis): fewer trabecular bone, attenuated osteoblastic function can’t keep up with osteoclasts.
Factors: genetics (bone mass, BMD), calcium intake, calcium absorption and vitamin D (less 1 alpha hydroxylase activity, decreased kidney response to PTH), exercise, cigarettes (decreased estrogen)

Front 47

Back 47

Primary HyperPTH

Hint 47

Metabolic bone disease
PTH → increased resorption by accelerated remodeling.
90% due to adenomas, 10% due to 4gland hyperplasias.
3 stages: early (osteoclast stimulation, cutting cones, peritrabecular fibrosis), Osteitis fibrosa (loose marrow fibrosis, hemosiderin-laden macrophages, hemorrhage from microfx and reactive woven bone), osteitis fibrosa cystica (cystic degeneration, gian cells, reactive bone, hemosiderin-laden macrophages.
“Brown tumors” : can look like giant cell tumors, check PTH!

Front 48

Back 48

Osteomalacia/Rickets

Hint 48

Metabolic bone disease
Osteomalacia: adults, inadequate mineralization of newly formed bone matrix
Rickets: kids, extensive changes within the growth plate (prolif and calcified cartilage zones continue to grow, becomes lobulated and irregular with endochondral calcification. Assoc with abnormal vit D, phosphate deficiency, defects in mineralization.

Rad: osteopenia, compression fractures, Pseudofractures of Milkman-Looser (radiolucent, transverse defects, no associated callus formation)

Histo: exaggeration of osteoid seams in thickness and proportion of trabecular surface covered.

Clin: muscle weakness, difuse aches and pain, or poorly localized bone pain and tenderness. Kids: apathetic, irritable, short attention span, bad bones and teeth, frontal bossing, rachitis rosary, pectus carinatum

Front 49

Back 49

Paget's disease

Hint 49

Disordered bone remodeling. >60yo, only one or a few bones. Hereditary and viral origins proposed.
Histo: 3 stages: hot (osteoclastic resorptive stage) (lytic lesions in the cortex, osteolysis, mild fibrosis, dilated marrow sinusoids). Mixed stage (osteblasts and osteoclasts, thickened cortical and cancellous bone, abundant but haphazard cellular activity). Cold (burnt out) stage (little cellular activity, disordered thickened bones, osteoclasts with >100 nuclei (killer clasts), prominent mosaic pattern of trabecular bone with paratrabecular fibrosis.
Clin: Pain, axial>appendicular, skull , pagetic steal (light-headedness due to increased blood demand), fx, arthritis, high-output cardiac failure, sarcomatous change (<1%), severe disease. Increased Alk Phos.
Most pts asx and require no treatment. Calcitonin, bisphosphonates, mithramycin can be used.

Front 50

Back 50

Tuberculosis (Pott's disease)

Hint 50

From focus elsewhere, affects the vertebral bodies, sparing lamina and spines
Usually thoracic > T11, cervical or lumbar
vertebral body collapses
histo: caseating granulomas, inflimmation, slow resorption of bone, little or no woven bone collapse
special studies: AFB
Cold abscess, psoas abscess

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Back 51

Fibrous dysplasia

Hint 51

Developmental disorder, fibrous and osseous elements
Rad: ground glass lesions, well-marginated
Monostotic: most common, 2nd/3rd decade, proximal femus, tibia, ribs, facial bones. Asymptomatic or fractures
Polyostotic: F>M, more than half of the skeleton is affected. Presents in childhood with fractures. May be quiescent at puberty, may be stimulated by pregnancy.
Tx: Repair of fractures.

Pathogenesis: increased cAMP from genetic mutations
Histo: benign fibroblastic tissue in loose whorled pattern, irregular spicules, no osteoblastic rims. 10% have islands of cartilage, can have cystic degeneration with hemosiderin-laden macrophages, hemorrhage, osteoclasts

<1% become sarcomas

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Back 52

Non-ossifying fibroma

Hint 52

Metaphysis
25% of kids 4-10yo, usually regresses, usually asx.
Rad: cortical, eccentric, well-demarcated, central lucent zone with scalloped scleroti margins
Gross: granular, dark red or brown
Histo: bland spindle cells, interlacing whorled pattern, multinucleated giant cells and foamy macrophages
Tx: curettage, bone grafting

Front 53

Back 53

Solitary bone cyst

Hint 53

benign, fluid-filled, unlilocular lesions
M>F
Metaphyseal, by growth plate, proximal humerus/femur
Disturbed bone growth by trauma, maybe due to hematoma, pressure → resorption of bone. Slow process.
Rad: well-marginated radiolucent (lytic) lesion
Histo: thing fibrous tissue, few giant cells and hemosiderin-laden macrophages, chronic inflammatory cells, reactive bone lining cyst. Osteoclasts on advancing edge. Proteinaceous material in cysts.

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Back 54

Aneurysmal bone cyst

Hint 54

uncommon, hyperemic, children and young adults, history of trauma
long bones and vertebrae
rad: lytic lesions on x-ray, fluid-fluid levels on MRI
rupture and hemorrhage is possible
gross: ballooned periosteum (blood-filled sponge)
histo: granulation tissue, scattered multinucleated giant cells, osteoid trabeculae

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Back 55

Osteoid osteoma

Hint 55

small painful lesion of osseous tissue (nidus) surrounded by halo of reacive bone formation
5-25yo
diaphysis, cortex of long bones, esp lower limbs
clin: pain (nocturnal, worse with EtOH, better with aspirin)
rad: sclerotic ortical based lesion with central nidus, <1cm
gross: spherical, hyperemic, soft. Soaks up tetracycline
histo: cellular, granulation tissue, osteoblasts, osteoclasts, thing trabecular bone more mature at the center with sclerotic reactive bone around
tx: curettage, elcrocautery, radio frequency ablation, mini-bloc excision

Front 56

Back 56

Osteoid osteoma

Hint 56

small painful lesion of osseous tissue (nidus) surrounded by halo of reacive bone formation
5-25yo
diaphysis, cortex of long bones, esp lower limbs
clin: pain (nocturnal, worse with EtOH, better with aspirin)
rad: sclerotic ortical based lesion with central nidus, <1cm
gross: spherical, hyperemic, soft. Soaks up tetracycline
histo: cellular, granulation tissue, osteoblasts, osteoclasts, thing trabecular bone more mature at the center with sclerotic reactive bone around
tx: curettage, elcrocautery, radio frequency ablation, mini-bloc excision

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Back 57

Osteoblastoma

Hint 57

similar to osteoid osteoma but larger, without nocturnal pain relieved by aspirin
spine and long bones, 10-35yo, M=F.
tx: curettage

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Back 58

Enchondroma

Hint 58

may be a hamartoma, but is neoplastic
asny age, asx, usually small bones of hands and feet. Small and slow-growing.
Rad: well-delineated radiolucent areas, stippled calcification
Gross: semi-translucent, few calcified area
Histo: well-differentiated hyaline cartilage, sparsely cellular, minimal cellular pleomorphism (except maybe hands and feet)
Tx: curettage

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Back 59

Enchondroma

Hint 59

may be a hamartoma, but is neoplastic
asny age, asx, usually small bones of hands and feet. Small and slow-growing.
Rad: well-delineated radiolucent areas, stippled calcification
Gross: semi-translucent, few calcified area
Histo: well-differentiated hyaline cartilage, sparsely cellular, minimal cellular pleomorphism (except maybe hands and feet)
Tx: curettage

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Back 60

Chondroblastoma

Hint 60

uncommon, benign. Epiphyseal of tubber femur, tibia and humerus
5-25yo, M>F
moderate pain, larger lesions can destroy the bone
rad: eccentric, radiolucent lesion, sharp borders. Mottled matrix on CT
goss: soft, compact, scattered gray or hemorrhagic area.
Histo: primite chondroblasts arranged in sheet of round/polyhedral cells with grooved nuclei. Calcification, multinucleated giant cells.
Tx: curettage, 10% recur.

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Back 61

Osteosarcoma

Hint 61

most common primary bone tumor
10-20yo, M>F, knee or shoulder, metaphyseal. Older ppl, it’s due to Paget or radiation.
RB and p53 mutations
Clin: mild/intermittent pain, swelling, tenderness, increased serum Alk Phos
Rad: lytic lesions, periosteum with rim of reactive bone (Codman’s triangle (uplifted periosteum), sunburst pattern)
Gross: variable
Histo: malignant osteoblasts produce woven bone, haphazard, foci of malignant cartilage, pleomorphic giant cells. Atypical mitotic figures.
Tx: adjuvant therapy, limb sparing surgery. 85% 5yr survival. Mets to lungs, also to bones, pleura, heart.

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Back 62

Chondrosarcoma

Hint 62

second most common primary malignant tumor
4-6th decades, M>F
clin: deep pain, usually central (pelvic, ribs, etc)
rad: lobulated, lytic mass with stippled/ring-like calcifications
histo: grading is important (1: well-differentiated (may look like enchondroma), 3- poorly differentiated). Rearrangement of chr17, t(9;22) in extraskeletal
tx: prog good for well-differentiated, less for high grade. Wide surgical excision

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Back 63

Chondrosarcoma

Hint 63

second most common primary malignant tumor
4-6th decades, M>F
clin: deep pain, usually central (pelvic, ribs, etc)
rad: lobulated, lytic mass with stippled/ring-like calcifications
histo: grading is important (1: well-differentiated (may look like enchondroma), 3- poorly differentiated). Rearrangement of chr17, t(9;22) in extraskeletal
tx: prog good for well-differentiated, less for high grade. Wide surgical excision

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Back 64

Ewing sarcoma

Hint 64

uncommon, malignant, M>F, rare in AA, small round cells
from primitive marrow elements , t(11;22) (worse prog)
May have fever and weakness, bone pain
rad: midshaft/diaphysis, onion-skin pattern (periosteal new bone reaction to keep in check).
Gross: soft and grayish, hemorrhage and focal necrosis, soft tissue expansion
Histo: sheets of packed small round cells, irregular nests of cells, little/no interstitial stroma, PAS positive, CD99 positive
Tx: chemo, radiation, surgery. 60-75% 5yr survival

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Back 65

Giant cell tumor of bone

Hint 65

locally aggressive, can be malignant, more in Asian countries, F>M, microfx.
rad: between metaphysis and epiphysis of long bones. Lytic lesion with little periosteal reaction. Thin bony shell, may extend into bone. Soap bubble.
Gross: hemorrhagic area, blood-filled sponge
histo: Mononuclear stroma (plump, large nucleus, mitoses), large osteoclastic multinucleated cells (random distribution). Rich vascularized stroma.
Tx: curettage, bone grafting, mets to lungs (5-10%)

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Back 66

Multiple myeloma

Hint 66

malignant plasma cell tumor, older people, M>F
rad: lytic due to cytokines, especially skull, spine, ribs, pelvis, femur
histo: sheets of plasma cells with varying maturity, amyloid in 10%, SPEP for monoclonal process
tx: chemotherapy, radiation
cause of death: kidney failure

Front 67

metastatic tumors

Back 67

most common malignant bone tumor
breast, prostate, lung, thyroid, kidney. Vertebral column is the most common.
thyroid, kidney, neuroblastoma and GI are lytic; prostate, breast, lung and stomach are blastic. Usually have a mix of lytic and blastic

Front 68

soft tissue

Back 68

Nodular fascitis

Hint 68

benign, rapidly-growing, from trauma.
Supl tissues of forearm, trunk, and back, usually in adults on extensor surfaces.
Histo: cellular mitotically active lesion with pleomarphic spindle cells. Exuberant granulation tissue.
Tx: excision

Front 69

soft tissue

Back 69

fibromatosis

Hint 69

locally invasive, slow-growing, don’t metastasize but recurr
risk: riabetics, alcoholics, epileptics
gross: large, whitish, poorly demarcated
histo: bland spindle cells (no pleoorphism or mitoses).
Palmar (dupuytren) (most common), plantar, penile (peyronie)

Front 70

soft tissue

Back 70

fibrosarcoma

Hint 70

malignant tumor of fibrobalsts, usually I thigh, adult, any age.
Congenital: t(12;15)
Gross: firm, sharply demarcated, necrosis and hemorrhage
Histo: pleomorphic fibroblasts in dense interlacing bundles and fascicles (herringbone pattern).
Bad prognosis

Front 71

soft tissue

Back 71

Malignant fibrous histiocytoma

Hint 71

most common sarcoma, due to radiation
older adults, deep fascia/skeletal muscle
histo: spindle shaped tumor cells, pleomorphism and mitotic figures. Histiocytic (macrophage) differentiation)
tx: 50% recur, mets to lungs, excision.

Front 72

soft tissue

Back 72

lipoma

Hint 72

most common soft tissue mass (benign)
gross: yellow, soft and lobulated
histo: well-differentiated adipocytes, no atypia or fibroblasts

Front 73

soft tissue

Back 73

liposarcoma

Hint 73

malignant, second most common
50yo, deep thigh, retroperitoneum, slow-growing. Myxoid variant: t(12;16)
gross: 5-10cm, may have necrosis, cysts, hemorrhage
histo: lipoblasts (signet ring) in a vascularized myxoid stroma
tx: prog depends on differentiation

Front 74

soft tissue

Back 74

leiomyoma

Hint 74

benign smooth muscle tumor, subcutaneous or vessel wall
gross: painful, firm yellow nodule
histo: bland spindle cells, low mitotic rate

Front 75

soft tissue

Back 75

leiomyosarcoma

Hint 75

malignant soft tissue tumor
gross: foci of necrosis, hemorrhage, cystic degeneration
histo: fascicle of spindle cells, cellular atypia, mitotic rate, mitotic rate → prognosis
tx: surgery, adjuvant therapy if high-grade. Most eventually metastasize.

Front 76

soft tissue

Back 76

rhabdomyosarcoma

Hint 76

children and young adults, from primitive mesenchyme
embryonal rhabdomyosarcoma: most common type, 3-12yo, usually head and neck.
Immunohistochemical stains make the diagnosis. Molecular studies for alveolar type: t(2;13) (bad prognosis). Botryoid and pleomorphic types also exist.
Tx: surgery, chemo, radiation.

Front 77

soft tissue

Back 77

rhabdomyosarcoma

Hint 77

children and young adults, from primitive mesenchyme
embryonal rhabdomyosarcoma: most common type, 3-12yo, usually head and neck.
Immunohistochemical stains make the diagnosis. Molecular studies for alveolar type: t(2;13) (bad prognosis). Botryoid and pleomorphic types also exist.
Tx: surgery, chemo, radiation.

Front 78

soft tissue

Back 78

synovial sarcoma

Hint 78

highly malignant, comes from tendon sheaths, bursa in joint capsules, <10% interarticular.
Adolescants and young adults in large joints.
T(x;18)
Gross: circumscribed, round or multilobular mass. Pseudocapsule, cystic changes.
Histo: spindle cell and epithelia-like area. Monophasic (spindled) variant also exists. Immunohistochemical stains for epithelial differentiation
Tx: high recurrence, mets in >60%, 50% to lung mets.