Bone Tumors B&B Flashcards
what are the classic causes of osteoclastic vs osteoblastic lesions, respectively?
multiple myeloma —> osteoclastic lesions: bone breakdown by metastasis
prostate cancer —> osteoblastic lesions: deposition of new bone
which patients do primary bone tumors most often affect?
children/young adults (growing), males (longer bones = more growth)
often involve lone bones, especially at knees
where are the 2 most frequent sites of pathologic fractures?
fracture in bone weakened by underlying abnormality, often from minor trauma
- proximal femur
- humerus
how do osteoid osteoma present?
small benign bone tumors of osteoblasts, occur mostly in young men (teens/20s) in appendicular skeleton - mostly at knee (tibia/fibula)
present with bone pain at night, responsive to aspirin
benign bone tumors of osteoblasts which may cause bone pain at night, but are responsive to aspirin
osteoid osteoma: occur on surface of cortex/diaphysis
osteoid core (radiolucent) surrounded by rim of woven bone
osteoid osteoma vs osteoblastoma
osteoid osteoma: small (<2cm) benign tumors of osteoblasts, cause bone pain at night but responsive to aspirin
osteoblastoma: larger tumor (>2cm) that often involves spine, pain not responsive to aspirin
what type of bone disorder may precede colon symptoms in Gardner’s Syndrome?
Gardner’s syndrome: variant of FAP (familial adenomatous polyposis), mutation in APC gene —> chronic polyp disorder
may present with osteomas (benign bone growths) in skull or mandible which may precede colon symptoms
how does the most common primary bone tumor present?
osteosarcoma: malignant tumor of osteoblasts, more common in males with bimodal age distribution (75% young adults, 25% older adults with bone disease)
—> painful/enlarging bone mass or pathologic fractures occurring in metaphysis of long bones
what does biopsy of osteosarcoma show?
malignant tumor of osteoblasts
histology —> pleomorphic cells (varying shapes) + irregular osteoid formation (appears pink due to protein)
what are 2 classic x-ray findings of osteosarcoma?
malignant tumor of osteoblasts
- Codman triangle: tumor breaks through cortex and lifts periosteum (looks like triangle on surface of bone on x-ray)
- sunburst/sunray sign: tiny bone fibers form in periosteum (looks like sunburst around metaphysis on x-ray)
what is development of osteosarcoma associated with? (3)
malignant tumor of osteoblasts
- prior radiation - following childhood cancer
- Paget’s disease
- familial cancer syndromes/germline mutations (familial retinoblastoma/Rb mutation, Li Fraumeni syndrome/p53 mutation)
how is osteosarcoma treated?
[malignant tumor of osteoblasts]
treat with ”en bloc” resection (removal of entire tumor in 1 piece + layer of healthy tissue) or amputation
all patients presumed to have metastasis - always treat with chemotherapy! either before (“neoadjuvant”) or after surgery
Pt is a 21yo M presenting with a painful and enlarging bone mass that was detected following a fracture of their femur metaphysis. X-ray shows the growth of tiny bone fibers around the periosteum in the shape of a sunburst. FMH is significant for familial retinoblastoma. How will the patient be treated?
osteosarcoma - histology shows Codman triangle (tumor breaks through cortex, lifts periosteum) and/or sunburst sign (around metaphysis)
tx: “en bloc” resection (remove entire tumor in 1 piece) or amputation + CHEMOTHERAPY (always presume metastasis!)
[associated with prior chemo, Paget’s disease, inherited genetic conditions
from which cells are Ewing sarcoma derived, and where do they occur?
malignant bone tumor of undifferentiated neuroectoderm cells
occur in diaphysis of long bones - usually femur, also tibia/fibula/humerus/pelvis
which bone tumors present at the youngest age?
Ewing sarcoma: malignant tumor of undifferentiated neuroectoderm cells, 80% <20 years old (M>F)
aggressive w/ early metastasis
aggressive malignant tumors occurring in the diaphysis of long bones, often with early metastasis
Ewing sarcoma: malignant tumor of undifferentiated neuroectoderm cells, 80% <20 years old (M>F)
how do patients with Ewing Sarcoma present?
Ewing sarcoma: malignant bone tumor of undifferentiated neuroectoderm cells, 80% <20 years old (M>F)
painful, growing mass that is warm/swollen, may have fever/leukocytosis
[appears similar to osteomyelitis, but blood cultures are neg. for bacteria]
how can Ewing Sarcoma be differentiated from osteomyelitis?
both present with warm/swollen mass, fever/leukocytosis
Ewing sarcoma: malignant bone tumor of undifferentiated neuroectoderm cells —> sterile blood cultures/ tumor aspiration
osteomyelitis: bone infection —> blood cultures pos. for bacteria
what is the classic x-ray and histology finding of Ewing sarcoma?
Ewing sarcoma: malignant bone tumor of undifferentiated neuroectoderm cells
x-ray - onion skin appearance due to layering near periosteum, caused by splitting of the cortex
histology - sheets of small, round cells (primitive cells)
what genetic defect is associated with most cases (85%) of Ewing sarcoma?
Ewing sarcoma: malignant bone tumor of undifferentiated neuroectoderm cells
associated with genetic translocation of chromosomes 11 and 22 —> fusion of EWSR1 (22) and FLI1 (11) genes, detected with FISH
Pt is a 17yo M presenting with a painful, growing mass over the diaphysis of the femur which is warm and swollen, as well as fever and leukocytosis. Tumor aspiration was found to be sterile. X-ray shows “onion skin” appearance of the bone. Genetic testing reveals a fusion of genes found on chromosome 22 and 11, respectively. What is the diagnosis?
Ewing sarcoma: malignant bone tumor of undifferentiated neuroectoderm cells, presents at young age and is aggressive w/ early metastasis
85% associated with genetic translocation of EWSR1 (ch22) and FL1 (ch11)
from which cells are giant cell tumors of the bone derived, and where do they usually occur?
aka osteoclastoma - benign tumor of osteoclasts, but locally aggressive (resorb lots of bone)
occur in epiphysis, most commonly in femur/tibia (at knee)
what drives giant cell tumors of the bone to grow?
aka osteoclastoma - benign tumor of osteoclasts, but locally aggressive (resorb lots of bone), occur in epiphysis
stromal tumor cells express high levels of RANK-L
tumor growing in the epiphysis of a long bone =
giant cell tumor, aka osteoclastoma: aka benign tumor of osteoclasts, but locally aggressive (resorb lots of bone)
where do osteochondromas occur?
benign cartilage-forming tumor due to lateral projection of growth plate at the metaphysis
if an osteochondroma becomes malignant, how does this occur?
benign cartilage-forming tumor due to lateral projection of growth plate at the metaphysis
rare to become chondrosarcoma, but if so due to malignant transformation of the cartilage cap
X-ray of a 15yo M reveals a cartilage-capped bone spur (“exostosis”) arising from lateral projection of the growth plate. What is the diagnosis, and how will this be treated?
osteochondroma: benign cartilage-forming tumor due to lateral projection of growth plate at the metaphysis
stopping growing once growth plate closes, treated with simple excision
[exostosis = new bone growth on surface of bone]
what causes fibrous dysplasia of the bone, and where does this occur?
benign tumor of woven bone surrounded by fibroblasts
occur in early adolescence, grow until growth plate closes
occur in medulla/diaphysis
what are the classic histology and x-ray findings of fibrous dysplasia?
benign tumor of woven bone surrounded by fibroblasts in the diaphysis/medulla
histology - wavy lines trabeculae of woven bone
x-ray - lytic lesions in diaphysis
where along bones do simple bone cysts (unicameral bone cysts) occur?
metaphysis of bone, most commonly proximal humerus or femur
where do chondromas occur?
benign cartilage tumor, either in medullary cavity (endochondroma) or surface of bone (juxtacortical chondroma)
occur in small bones of hands and feet
where do chondromas vs chondrosarcomas occur?
chondroma = benign cartilage tumor, occur in small bones of hands and feet
chondrosarcoma = malignant cartilage tumor, occur centrally (pelvis, shoulder, ribs)
patient presenting with bone pain/ fractures with LOW calcium and HIGH PTH = problem due to …
low vitamin D - either lack in diet/sunlight, malabsorption, renal failure (problem activating vitamin D)
which of the following would NOT occur in the diaphysis?
a. Ewing sarcoma
b. Giant cell tumor
c. Osteoid osteoma
d. Fibrous dysplasia
e. metastasis from another site
b. giant cell tumor - occurs in epiphysis
all others occur in diaphysis of long bone
what is the most common type of long bone tumor to occur in the metaphysis?
osteosarcoma - most common type of primary bone tumor
how does the bone variant of Langerhans cell histiocytosis present?
malignant proliferation of Langerhans cells, bone variant causes eosinophilic granuloma —> bone mass in skull of children
differentiate from bone tumor by Langerhans cells and eosinophils in biopsy
[Langerhans = dendritic cells of myeloid origin, but similar to histiocytes, aka tissue macrophages]
bone mass in skull of child with eosinophils in biopsy =
Langerhans cell histiocytosis: growth of Langerhans cells, bone variant causes eosinophilic granuloma —> bone mass in skull of children
how can Langerhans cell histiocytosis be differentiated from bone tumors?
malignant proliferation of Langerhans cells, bone variant causes eosinophilic granuloma —> bone mass in skull of children
biopsy shows Langerhans cells and eosinophils (not found in bone tumors)
