Bone Tumors Flashcards
clinical presentation of bone tumors
pain, mass, pathological fracture, asymptomatic
diagnostic factors
age, sex, skeletal location (bone, area of bone), radiographic appearance
sclerotic margin indicates?
benign, slowly-growing neoplasm
ill-defined margin indicates?
malignant, rapidly growing neoplasm
solid, ivory-like pattern indicates?
malignant bone matrix-forming tumors
rings and arcs (moth-eaten holes) indicate?
chondroid matrix-forming tumors
most common major primary tumors involving bones
hematopoietic (40%), myeloma + malignant lymphoma
most common primary bone malignancy?
osteosarcoma
benign bone-forming tumors
osteoid osteoma & osteoblastoma (histologically similar)
osteoid osteoma characteristics
long bones, femur & tibia, < 2 cm, night pain that responds to aspirin. radiolucent lesion within sclerotic cortex
osteoblastoma characteristics
vertebrae or long bone metaphysis, > 2 cm, painful, not responsive to aspirin, expansile radio-lucency with mottling
malignant mesenchymal tumor in which cells produce bony matrix or bone
osteosarcoma
osteosarcoma
most common sarcoma of bone (35%), bimodal age distribution (M > F) mean age 15, 2nd peak 55-80. infiltrative tumor extending into soft tissue. malignant cells producing osteoid.
osteosarcoma location + mets?
metaphysis of long bones, may be polyostotic. hematogeneous spread to lungs common
osteosarcoma pathogenesis
inherited mutant allele of RB gene, mutation of p53 suppressor gene (Li-Fraumeni), overexpression of MDM2, INK4 and p16; sites of bone growth/dz (Paget), prior irradiation
osteosarcoma radiography
poorly delineated, bone destruction, cortical disruption, bone matrix, soft tissue extension, codman’s triangle
osteosarcoma treatment
- neo-adjuvant chemo
2. surgical resection
osteosarcoma prognosis
post chemo: 60-65% 3-5 year survival if non-mets. (before chemo 5 year survival 20%) >90% necrosis after chemo means near 90% survival.
cartilaginous tumors
osteochondroma, enchondroma, multiple chondromatosis
osteochondroma
most common benign bone tumor. metaphysis of long bones. autosomal dominant mutations in EXT-1 hereditary multiple exostoses (40% risk for malignant transformation).
enchondroma
benign hyaline cartilage lesion. intramedullary chondroma. usually asymptomatic, on appendicular skeleton (eg finger)
periosteal chondroma
juxtacortical chondroma (on cortical surface under periosteum)
enchondroma on x-ray, micro?
x-rays: lytic, lobulated, cortical thinning.
micro: lobules of hyaline cartilage, minimal atypia
enchondroma treatment
non, unless lesion shows changes (symptomatic, or evidence of recent growth after skeletal maturity)
multiple chondromatosis
frequent point mutations in IDH1 or IDH2
ollier’s disease
multiple enchondromata, regional distribution, w or w/o severe skeletal malformation
maffucci’s syndrome
multiple enchondromata + ANGIOMATA. severe skeletal malformation. higher incidence of malignant transformation into chondrosarcoma
chondrosarcoma
malignant, neoplastic cells produce cartilaginous matrix. second most common bone sarcoma (26%). older adults, above 40-50. peak during 6th and 7th decades. in central skeleton.
chondrosarcoma imaging
medullary loction. present calcifications (lost in grade 3 tumors). cortical erosion or destruction. occasional soft tissue extension. popcorn like on xray
chondrosarcoma pathology
more cellular, nuclei more pleomorphic than in enchondromas. binucleation frequent. myxoid change. size and grade correlate w behavior.
chondrosarcoma survival
grades 1, 2 5 year survival: 80-90%, grade 3 5 yr 29% (pulmonary mets)
chondrosarcoma variants
de-differentiated
de-differentiated chondrosarcoma
cells look generic, no cartilage formation
fibrous bone tumors
non-ossifying fibroma, fibrous dysplasia
non-ossifying fibroma
common devo cortical defect, 25% multifocal. tibia, femur (metaphysis) in 1-3rd decades. eccentric, lytic, peripheral sclerosis. incidental finding or pathologic fracture. starry night histo.
fibrous dysplasia
devo arrest of bone. monostotic is most common- adolescents: ribs, jaw, femur. polyostotic- infancy/childhood: crippling deformities, craniofacial involvement
McCune-Albright syndrome
polyostotic FD with endocrinopathies, cafe-au-lait spots. rare, F > M. sexual precocity, acromegaly, cushing. activating germline mutations of GNAS lead to excess cAMP leads to endocrine gland hyperfunction
fibrous dysplasia on radiograph
expansile, circumscribed, thinned cortex, ground glass appearance, may be multiple
fibrous dysplasia pathology
haphazard, curvilinear chinese characters surrounded by fibroblastic stroma. no significant osteoblastic rimming.
ewing sarcoma /PNET
2nd most common malignant bone tumor in kids. M > F. adolescents, young adults. painful, often enlarging mass on diaphysis of long tubular bones, ribs and pelvis
ewing sarcoma /PNET x-ray
moth eaten, permeative medullary lesion with large soft tissue mass. onion skin pattern.
ewing sarcoma /PNET pathology
sheets of primitive small round blue cells, neural phenotype. CD99. abundant glycogen. hemorrhage and necrosis common. mitotic activity
ewing sarcoma /PNET pathogenesis
EWS involved in > 95% of ES/PNET. t(11;22) in 85% of tumors (EWS on 22q fused with FLI-1 transcription factor on 11q)
ewing sarcoma /PNET treatment
chemo + surgery, radiation therapy. stage 1: 5 year survival 70% w chemo/RT
giant cell tumor of bone
20-40 yo, older adolescents; F > M. epiphyseal location (knee, prox humerus, radius). most are benign, locally aggressive, may destroy cortex of bone and extend into soft tissue. infiltrative but no mets.
metastatic bone tumors
most common malignant bone tumor esp in adults. mostly multiple. solitary lesions may mimic primary bone tumor; 70% to axial skeleton, mostly lytic, may be blastic. 80%: BLT-KP.
