Bone Tumors Flashcards
osteoblast (first aid)
*builds bone by secreting collagen and catalyzing mineralization in alkaline environment via ALP
*differentiates from mesenchymal stem cells in periosteum
*osteoblastic activity measured by bone ALP, osteocalcin, propeptides of type I procollagen
osteoclast (first aid)
*dissolves (“Crushes”) bone by secreting H+ and collagenases
*differentiates from a fusion of monocyte/macrophage lineage precursors
*RANK receptors on osteoclasts are stimulated by RANKL (RANK ligand, expressed on osteoblasts)
*OPG binds RANKL to prevent RANK-RANKL interaction → decreased osteoclast activity
parts of the bone: epiphysis
*the end of a long bone between the growth plate and the joint, in which there is the center for ossification
parts of the bone: metaphysis
*the portion of a developing long bone between the diaphysis (shaft) and the epiphysis (end)
*the growing portion of the bone
parts of the bone: diaphysis
*the tubular shaft that runs between the proximal and distal ends of the long bone
tumors in the bone - general principles
*metastatic disease is far more common than primary bone tumors
*common cancers that metastasize to bone:
-prostate
-multiple myeloma
-breast
-lung
-thyroid
-kidney
*primary bone tumors are rare
benign primary bone tumors
*osteoid osteoma
*osteoma
*osteoblastoma
*osteochondroma
*chondroblastoma
*giant cell tumor of bone
recall - “-oma” indicates benign
malignant primary bone tumors
*osteosarcoma
*Ewing sarcoma
*chondrosarcoma
recall - “-sarcoma” indicates malignant
most common site of metastasis of primary bone tumors
- lungs
- other bones
approach for bone tumors
- look for patterns
- age of patient
- location of lesion
- other clinical history: painful vs. painless; response to medications
- radiology patterns
bone tumors by location: diaphysis
*osteoid osteoma
*Ewing sarcoma
bone tumors by location: metaphysis
*osteosarcoma
*osteochondroma
bone tumors by location: epiphysis
*giant cell tumor
bone tumors by location: face
*osteoma
bone tumors by location: hands/feet
*chondroma
bone tumors by location: spine
*osteoblastoma
*chondrosarcoma
osteoid osteoma - epidemiology
*most commonly: young males (teens to early 20s)
*adults < 25 yo
*males > females
recall: BENIGN bone tumor; location = DIAPHYSIS
osteoid osteoma - type of tumor
*benign tumor of osteoblasts
recall: BENIGN bone tumor; location = DIAPHYSIS
osteoid osteoma - location
*cortex of long bones (diaphysis)
recall: BENIGN bone tumor; location = DIAPHYSIS
osteoid osteoma - characteristics
*classically presents as bone pain, worse at night caused by prostaglandins
*relieved by NSAIDs
recall: BENIGN bone tumor; location = DIAPHYSIS
osteoid osteoma - radiology
*bony mass with radiolucent osteoid core with reactive bone formation
recall: BENIGN bone tumor; location = DIAPHYSIS
Ewing Sarcoma - epidemiology
*young males < 15yo
*classically, white pts
recall: MALIGNANT bone tumor; location = DIAPHYSIS
Ewing Sarcoma - type of tumor
*malignant tumor of small blue cells of neuroectoderm
recall: MALIGNANT bone tumor; location = DIAPHYSIS
Ewing Sarcoma - location
*diaphysis of long bones (esp femur)
*can be pelvic flat bones
recall: MALIGNANT bone tumor; location = DIAPHYSIS
Ewing Sarcoma - characteristics
*classically presents with painful, warm, swollen mass, plus fever
*leukocytosis
*histology: anaplastic small blue cells of neuroectodermal (mesenchymal) origin (resemble lymphocytes)
recall: MALIGNANT bone tumor; location = DIAPHYSIS
Ewing Sarcoma - FISH genetics
t(11;22)
fusion protein: EWS-FLI1
recall: MALIGNANT bone tumor; location = DIAPHYSIS
Ewing Sarcoma - radiology
*layering of periosteum looking like an onion skin
recall: MALIGNANT bone tumor; location = DIAPHYSIS
Ewing Sarcoma - treatment
*aggressive with early metastases, but responsive to chemotherapy
recall: MALIGNANT bone tumor; location = DIAPHYSIS
osteosarcoma - epidemiology
*most common in males < 20 yo
*can present in older adults due to other associated conditions:
-Paget’s disease of the bone
-radiation
-familial retinoblastoma
-Li Fraumeni syndrome
recall: MALIGNANT bone tumor; location = METAPHYSIS
osteosarcoma - type of tumor
*malignant tumor of the osteoblasts
recall: location = METAPHYSIS
osteosarcoma - location
*metaphysis of long bones (often in knee region)
recall: MALIGNANT bone tumor; location = METAPHYSIS
osteosarcoma - characteristics
*classically presents with a painful enlarging mass or a pathologic fracture
recall: MALIGNANT bone tumor; location = METAPHYSIS
osteosarcoma - radiology
1. Codman’s triangle (from elevation of periosteum - left)
2. sunburst pattern - right
recall: MALIGNANT bone tumor; location = METAPHYSIS
Codman’s triangle - image & associated tumor
*associated with osteosarcoma
*due to elevation of the periosteum
recall: MALIGNANT bone tumor; location = METAPHYSIS
sunburst pattern on X-ray - image & associated tumor
*associated with osteosarcoma
recall: MALIGNANT bone tumor; location = METAPHYSIS
osteosarcoma - treatment
*presumed there are metastases
*tx = surgery followed by chemotherapy
recall: MALIGNANT bone tumor; location = METAPHYSIS
osteochondroma - epidemiology
*most common benign bone tumor
*males < 25 years old
recall: BENIGN bone tumor; location = METAPHYSIS
osteochondroma - type of tumor
*benign tumor
recall: location = METAPHYSIS
osteochondroma - location
*metaphysis (at growth plate)
*most common around knee to distal femur
recall: BENIGN bone tumor; location = METAPHYSIS
osteochondroma - characteristics
*lateral bony projection of growth plate, covered by cartilaginous cap; points AWAY from joint
*asymptomatic often
*EXT1 or EXT2 gene mutation
recall: BENIGN bone tumor; location = METAPHYSIS
osteochondroma - radiology
*lateral bony projections of growth plate (continuous with marrow space) covered by cartilaginous cap pointing away from the joint
recall: BENIGN bone tumor; location = METAPHYSIS
osteochondroma - treatment
*stops growing when growth place closes
*surgical excision or watch
*rarely transforms to chondrosarcoma
recall: BENIGN bone tumor; location = METAPHYSIS
giant cell tumor - epidemiology
*20-40 years old
*females > males (slight female predominance)
recall: BENIGN bone tumor; location = EPIPHYSIS
giant cell tumor - type of tumor
*benign tumor of osteoclasts
recall: location = EPIPHYSIS
giant cell tumor - location
*epiphysis of long bones
*after skeletal maturation
*often in knee region
recall: BENIGN bone tumor; location = EPIPHYSIS
giant cell tumor - clinical symptoms
*joint pain
*swelling
recall: BENIGN bone tumor; location = EPIPHYSIS
giant cell tumor - pathology
*multinucleated giant cells
*expressing RANKL
recall: BENIGN bone tumor; location = EPIPHYSIS
giant cell tumor - radiology
*“soap-bubble” appearance on x-ray
recall: BENIGN bone tumor; location = EPIPHYSIS
giant cell tumor - treatment
*varied - based on location, age, etc
recall: BENIGN bone tumor; location = EPIPHYSIS
osteoma - epidemiology
*middle aged adults
*association: Gardner syndrome
recall: BENIGN bone tumor; location = FACIAL BONES
osteoma - type of tumor
*benign tumor
recall: location = FACIAL BONES
osteoma - location
*surface of facial bones (skull, mandible)
recall: BENIGN bone tumor; location = FACIAL BONES
chondroma - type of tumor
*benign tumor of cartilage
recall: location = small bones of hands/feet
chondroma - location
*medulla of small bones of hands/feet
recall: BENIGN tumor; location = small bones of hands/feet
osteoblastoma - epidemiology
*males > females
recall: BENIGN tumor; location = VERTEBRAE
osteoblastoma - type of tumor
*benign tumor
recall: location = VERTEBRAE
osteoblastoma - location
*vertebrae
recall: BENIGN tumor; location = VERTEBRAE
osteoblastoma - characteristics
*pain
*NOT RESPONSIVE to NSAIDs (contrast to osteoid ostoma)
recall: BENIGN tumor
chondrosarcoma - epidemiology
*adults > 50 yo
recall: MALIGNANT tumor
chondrosarcoma - type of tumor
*malignant tumor of chondrocytes
chondrosarcoma - location
*medulla of pelvis, proximal femur, and humerus
recall: MALIGNANT tumor
chondrosarcoma - radiology
*intralesional calcifications
*cortex breach, endosteal erosion
recall: MALIGNANT tumor
“soap bubble” appearance on radiology - description
*expansile, osteolytic, radiolucent lesion with a non-sclerotic, sharply defined border
*associated with the benign giant cell tumor of bone
