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AAOS Section 11 - Oncology > Chapter 143 - Benign Bone Tumors and Reactive Lesions > Flashcards

Chapter 143 - Benign Bone Tumors and Reactive Lesions Flashcards

1
Q

Osteoid osteoma - presentation

A

young patient
Male 2:1
night pain relieve by NSAIDs

Common locations: Femur, tibia, posterior vertebral elements, humerus
- proximal femur is most common
- hip is most common intra-articular location

Metaphysis or diaphysis - diaphysis more common

if related to a scoli - concavity of the curve and 2/2 paraspinal spasm 2/2 lesion pain - take the lesion out, scoli resolves

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2
Q

Osteoid Osteoma - radiology

A

round, well circumscribed intra-cortical lesion with a radiolucent nidus
- with a periosteal reaction

intense focal uptake on technetium 99 scans

MRI with extensive surrounding edema

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3
Q

Osteoid Osteoma - path

A
  • trabeculae lined with plump osteoblasts
  • on low power images - sharply demarcated nidus surrounded by dense cortical bone
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4
Q

Osteoid osteoma - treatment

A
  • radiofrequency ablation

EXCEPT IN SPINE
- resection vs burring

  • in proximal femur - will need bone grafting and internal fixation as well
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5
Q

Osteoblastoma - presentation

A

rare, aggressive, benign osteoblastic tumor
between age 10-30
male2:female1

genetics: FOS/FOSB rearrangements

slowly progressive, dull aching pain, less severe than osteoid osteoma

NO night pain, NSAIDS dont help

COmmon locations:
- posterior elements of spine (number 1)
metaphysis/diaphysis of tibia/femur

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6
Q

Osteoblatoma - radiographic features

A

radiolucent lesion 2-10 cm

2/3 are cortical based, 1/3 are medullary

expansile, invades soft tissue, with rim of reactive bone

ddx:
osteosarc, abc, osteomyelitis, osteoid osteoma

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7
Q

Osteoblastoma - path

A

interwoven trabeculae with fibrovascular connective tissue

giant cells present

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8
Q

differentiating osteoid osteoma from osteoblastoma

A
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9
Q

osteoblastoma - treatment

A

curretage and bone grafting

en bloc resection for spinal lesions
- leave the nerve roots

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10
Q

parosteal osteoma - presentation

A

females>males
30s-40s yo

often a history of local trauma

long history of gradual swelling or dull pain

classically found int he craniofacial bones
less frequently is tibia/femur, pelvis, vertebrae

multiple lesions: gardner syndrome - colonic polyps, fibromatosis, cutaneous lesions, sub-cu lesions - autosomal dominant

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11
Q

paroseal osteoma - radiology

A

uniform, radiodense lesion, broad base
1-8cm
NO cortical or medullary invasion

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12
Q

parosteal osteoma - path

A

mature, hypocellular lamellar bone

no atypia

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13
Q

enchondroma presenation

A

benign bone tumor composed of mature hyaline cartilage within the medullary canal

age 20-50

incidentaloma

IDH1, IDH2 somatic mutations

enchondroma is the most common bone tumor in the hand
other common locations: proximal humerus, distal femur, proximal tibia

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14
Q

enchondroma - radiology

A

well defined, lucent, cental medulalr lesion with stippled calcifications

1-10 cm

MINIMAL cortical erosion (<50% width of the cortex)
except in the hands where cortices may be thinned and expanded

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15
Q

enchondroma - pathology

A

blue-gray lobulated cartilage variable amount of calcification

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16
Q

enchondroma - treatment

A

none necessary

curretage and grafting if painful

pathologic fx, especially in small bone should be allowed to heal before curretage and grafting

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17
Q

enchondroma - related conditions

A

Ollier’s disease
- multiple enchondromas
- tend to be on one side of the body
- sporadic inheritance
- failure of normal endochondral ossification
- IDH1/IDH2 mutations
- increased risk of chondrosarcoma transformation of an enchondroma - 25-30%

Maffucci Syndrome
- multiple enchondromas + soft tissue angiomas
- angiomas present on XR as phleboliths
- IDH1/IDH2 mutations
- increased risk of malignant transformation of an enchondroma to a low grade chondrosarcoma
- very high risk of developing retroperitoneal soft tissue sarcomas (fatal visceral malignancy)

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18
Q

osteochondroma - demographics

A

most common benign bone tumor

most identified in the first two decades of life

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19
Q

oteochondroma - genetics

A

trapped growth plate cartilage that herniates thru the cortex

defect in the perichondral node of ranvier

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20
Q

osteochondroma - presentation

A

most are solitary and asymptomatic
range from <3cm to 15cm

continue to grow until skeletal maturity

occur most commonly around the knee
- distal femur
- proximal tibia
also: proximal humerus, pelvis (high rate of malignant transformation), and posterior elements of spine

risk of malignant degeneration of solitary osteochondroma 1%

sessile lesions more commonly malignant transformation

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21
Q

osteochondroma - treatment

A

try to delay until skeletal maturity to decrease risk of recurrence

surrounding perichondrium over cartilage cap needs to be removed in order to prevent local recurrence

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22
Q

Multiple hereditary exostosis

A

EXT1/EXT2 gene defect -> heparan sulfate deficiency, autosomal dominant

risk of malignant transformation id higher than solitary osteochondroma (5-10%)

most common location of secondary chondrosarcoma is a sessile osteochondroma on the pelvis

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23
Q

Chondroblastoma - presentation

A

rare, benign bone tumor differentiated by giant cell by chondroid matrix

male2:female1
<25yo

location of lesions:
surround the knee - distal femur epiphysis most common, proximal tibial epiphysis next, proximal humerus, proximal femur, calcaneus

can develop benign pulm mets

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24
Q

Chondroblastoma - imaging

A

small round tumors - epiphyseal or apophyseal
+/- extension to the metaphysis
1-4cm
sclerotic rim
cortical expansion often present, invasion of surrounding soft tissue is not
stippled calcifications in 40%

MRI will show extensive edema around the lesion

25
chondroblastoma - path
- background of mononuclear cells few/scattered giant cells focal chondroid matrix S100+!!! chicken wire calcifications
26
chondroblastoma - treatment
curretage and grafting phenol, liquid nitrogen, or argon adjuvant
27
chondromyxoid fibroma - presentation
2nd/3rd decades of life slight male predilection painful lesions long bones of the lower extremity/pelvis
28
chondromyxoid fibroma - imaging
lucent lesion ECCENTRIC Metaphyseal long bone lesion thinning and expansion of cortical bone sharp, scalloped rim - shark bite rare to have intralesional calcifications
29
chondromyxoid fibroma - path
look for THREE regions: chondroid, myxoid, fibromatous - lobulated with peripheral hypercellularity - within lobules, spindle shaped cells areas of bizarre nuclei are common
30
Non-ossifying fibroma - presentation
- children 5-15 - up to 30% of kids with open physes wil have an NOF usually incidental finding can be assoicated with neurofibromatosis Jaffee-Campanacci syndrome (cafe au lait spots, mental retardation, heart, eyes, gonad abnormalities) common locations: - long bones of lower extremities (80%) +/- pathologic fracture
31
non-ossifying fibroma - radiology
- eccentric - lytic - cortically based with sclerotic rim - metaphyseal but migrate toward the diaphysis with age
32
Non-ossifying fibroma - path
- prominent hemosiderin component - foamy macrophages (xanthomatous reaction) - prominent storiform pattern of fibrohystiocytic cells - variable giant cell #
33
treatment - non-ossifying fibroma
pathologic fractures are allowed to heal then curretage and grafting most will resolve spontaneously curettage and grafting if very symptomatic
34
Fibrous Dysplasia - presentation
hamartomatous fibro-osseous proliferation within bone females>males, generally age <30 inability to produce mature lamellar bone common locations: facial involvement, maxilla, proximal femur, rib, tibia
35
fibrous dysplasia genetics
GNASalpha mutation -> perpetually active adenylate cyclase-cyclic adenosine monophosphate activation
36
mazabraud syndrome
polyostotic fibrous dysplasia multiple intramuscular myxoma females>males, lower etremities
37
McCune Albright syndrome
polyostotic fibrous dysplasia precocious puberty pigmented skin lesions (irregular borders) unilateral bone lesions, unilateral skin lesions
38
fibrous dysplasia - radiology
central lytic lesion within the medullary canal, usually diaphysis/metaphysis expansile with cortical thinning ground glass appearance
39
fibrous dysplasia - path
gross tissue: yellow-white, gritty tissue micro: poorly mineralized immature fibrous tissue surrounding islands of irregular poorly mineralized trabeculae of woven bone
40
fibrous dysplasia - treatment
curettage and CORTICAL grafting - dont use cancellous graft, it will just get replaced by dysplastic bone *** Bisphosphonates helpful here!
41
osteofibrous dysplasia
males>females kids <10 associated with trisomy 7/8/12/22 anterior tibial shaft lesion - well defined only anterior tibial cortex avoid surgery - brace if necessary spontaneously regress at skeletal maturity
42
desmoplastic fibroma
honeycomb/trabeculated appearance tumor is hypocellular and similar to scar tissue tx is curettage and grafting wide resection in expendable bones
43
Langerhans cell histiocytosis - presentation
clonal disease CD1a positive immature dendritic cells BRAF oncogene positive kids <20 male 2:1 common location: skull, rib, scapula, vertebrae (thoracic>lumbsr>cervical), long bones, pelvis
44
langerhans cell histiocytosis - rads
punched out lesion with thick periosteal reaction vertebral plana
45
Langerhans cell histiocytosis - path
histiocytes with coffee bean nuclei eosinophilic cytoplasm CD1a staining giant cells often present scanning electron microscopy - birbeck granules - tennis racket shaped granules
46
langerhans cell histiocytosis - treatment
solitary lesions: methylprednisolone injection curettage and grafting vertebral plana: bracing alone
47
unicameral bone cyst - presentation
serous fluid filled bone cyst patients <20 pathologic fracture after minor trauma most common locations: proximal humerus proximal femur ileum, calc less common
48
Unicameral bone cyst imaging
purely lytic lesion in medullary canal cortical thinning with no soft tissue extension bone expansion does not exceed width of physis fallen leaf sign
49
unicameral bone cyst - path
clear, serous fluid in cavity cyst lining is thin, fibrous membrane cementum spherules (calcified eosinophilic fibrinous material)
50
unicameral bone cyst - treatment
injection of methylprednisolone
51
aneurysmal bone cyst - presentation
75% younger than 20 USP6 mutations painful lesion, with associated swelling most common locations: distal femur, proximal tibia, pelvis, spine (posterior elements)
52
aneurysmal bone cyst - radiology
eccentric lytic lesion metaphyseal lesion aggressive destruction and expnsion of the cortex with soft tissue infiltration periosteal rim can expand wider than the epiphyseal plate t2 mri with fluid fluid levels
53
ABC - path
blood filled cyst solid areas are common no cellular atypia, but mitoses are common
54
abc - treatment
curettage and grafting highest local recurrence in young patients with open physeal plates embolization or sclerotherapy for pelvic/spinal lesions that cant be resected
55
Giant cell tumor of bone - presentation
benign, agressive bone lesion age 30-50 females>males c-myc, n-myc, c-fos oncogene mutations pain x 2-3 months with swelling decreased ROM around a joint locations: distal femur proximal tibia distal radius, proximal humerus, proximal femur, sacrum, pelvis
56
giant cell tumor of bone - radiology
eccentric, lytic lesion of the epiphysis, metaphysis of long bones can extend to the subchondral surface without a sclerotic rim ANTERIOR vertebral body when spine is involved commonly have an ABC component secondarily
57
giant cell tumor of bone - path
gross specimen: soft, red-brown, hemorrhagic, necrotic micro: tons of multinucleated gint cells in a background of stromal cells (the stromal cells are actually the neoplastic cell)
58
GCT of bone - treatment
thorough curettage and high speed burr methylmethacrylate back fill embolization should be used for pelvic or spinal lesions along with surgery denosumab is FDA approved for unresectable GCT - causes GCT to ossify benign pulmonary mets in 2%

AAOS Section 11 - Oncology (9 decks)

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