Intro to Neoplasia of Bone Tissues Flashcards
Mutations of what types of genes contribute to cancer genetics?
- oncogenes
- tumor suppressor genes
- anti-apoptotic/pro-apoptotic genes
What is the result of mutated oncogenes?
increased cell proliferation
(turns on oncogenes, should be quiescent)
What is the function of tumor suppressor genes?
decrease uncontrolled proliferation
___-apoptotic genes would be present in a malignant neoplasia
anti-apoptotic (stop cells from dying)
____-apoptotic genes are involved in fighting against a malignant neoplasia
pro-apoptotic (make cells die)
What pathologies are risk factors for neoplasia of bone?
- Paget disease
- Chronic infection (osteomyelitis)
- Fibrous dysplasia (<1%)
- Some benign tumors (eg. osteochondroma -> osteosarcoma)
Patients with Pagets disease are particularly at risk of developing what malignant neoplasia?
osteosarcoma
What is the bimodal distribution of osteosarcoma?
- usually <25 yrs
- > 50 yrs (Pagets/radiation)
Why is radiation therapy a risk factor for malignancy?
- scrambles chromosome cross-linking -> cell death
- can also turn on oncogenes & turn off tumor suppressor genes
Genes that produce proteins which regulate cellular replication by slowing proliferation are called ____
tumor suppressor genes
Where do primary bone tumors originate?
in a bone tissue cell line:
- bone
- cartilage
- fibroblast
- blood cells/vessels
- marrow
(anything that contributes to normal bone)
Where do the majority of primary bone tumors occur?
distal femur or proximal tibia (metaphyses)
(knee)
Secondary bone tumors are considered ____ disease
metastatic
Secondary bone tumors originate in ____ and spread to ____
another tissue –> bone
What part of bone do secondary bone tumors usually spread to?
marrow (nutrient-rich)
Describe the borders/margins of benign tumors
- well-circumscribed
- narrow/short ZoT (non-aggressive)
Describe the borders/margins of malignant tumors
- poorly defined
- wide/long ZoT (aggressive/invasive)
Benign tumors have a ____ rate of growth
linear
(will eventually stop)
Malignant tumors have a ____ rate of growth
exponential
Cells of benign tumors generally have what function?
tissue of origin
Cells of malignant tumors generally have what function?
replication
Are benign tumors generally painful?
usually painless, may cause adjacent tissue pain
Are malignant tumors generally painful?
- painful/insidious onset
- possibly other cardinal signs of inflammation
Are benign tumors capable of metastasis?
no
Are malignant tumors capable of metastasis?
yes
Describe the prognosis of benign versus malignant tumors
Benign: good
Malignant: poor (depends on grade)
Define metastatic neoplasia
spread of neoplastic cells from one tissue to another otherwise healthy tissue
Define metastatic calcification
deposition of calcium in otherwise healthy tissue
What are the metastatic routes of spread?
- hematogenous
- lymphatic
- direct extension
What is the most common metastatic route of spread? Why?
hematogenous
- tumors create vascular supply (angiogenesis)
- O2 + glucose available
- malignant cells shed easily -> into bloodstream
Why are the lumbar spine, pelvis and proximal femur common areas of metastasis?
- ^^blood in area
- gravity
- Batson’s venous plexus (no valves)
What are the lab findings of benign tumors of bone?
normal
What are the radiographic characteristics of benign tumors of bone?
non-aggressive:
- no soft tissue involvement
- cortex (usually) intact
- periosteum unaffected (or solid Rxn)
- short/narrow ZoT
MALT lymphoma is classified as a ____-grade malignancy
low
(mucosal-associated lymphoid tissue)
What are the lab findings of malignant tumors of bone?
Abnormal:
- ^ESR
- ^CRP
- anemia
- abnormal WBC counts (seen w/ recurrent infections)
Normal ESR and CRP labs would rule out a ____ tumor
(aggressive) malignant
Why would a malignant bone tumor cause anemia?
- replacement of bone marrow = decreased RBCs/WBCs
- manifests as fatigue
What are the radiographic characteristics of malignant bone tumors?
- soft tissue involvement
- cortex disruption
- periosteal disruption/lifting (Codman’s, laminated, spiculated)
- long/wide ZoT
A soft tissue mass extending beyond bone indicates a (primary/secondary) malignancy of bone
primary
(mets to bone rarely involves soft tissue)
How are neoplasias of bone tissue diagnosed?
- traumatic/pathologic determinism (patho Fx)
- radiographic evidence
- other imaging
- tissue biopsy
What is the only definitive diagnosis of a neoplasia?
tissue biopsy
In what situation would you NOT want to get a biopsy?
in highly vascular tissue where there is concern of ^bleeding or spread along biopsy tract
(eg. metastatic melanoma or chondrosarcoma)
What does the prefix of a neoplasia usually indicate?
tissue of origin
What does the suffix -oma indicate?
benign MSK
What does the suffix -sarcoma indicate?
malignant MSK
A chondroma is a ____ tumor of ____ cells
benign
cartilage
Why does neoplasia in bone tissues rarely cross open growth plates?
- not much blood to physis (obtains nutrients via diffusion)
- once growth plate closes, no longer a barrier
A patient with a ____ primary bone tumor will frequently present with pain and possibly swelling
malignant
A radiographic finding for a ____ tumor is ____.
(Select all that apply)
A) malignant; short zone of transition
B) benign; solid periosteal lifting
C) malignant; cortical disruption
D) benign; soft tissue involvement
B & C
Giant cell tumors start in the ____ of bone and grow toward the ____
metaphysis -> epiphysis
What benign tumors are commonly found in the epiphysis/apophysis of bone?
- chondroblastoma
- giant cell tumor
What benign tumors are commonly found in the metaphysis of bone?
- osteoid osteoma
- osteoblastoma
- osteochondroma
- enchondroma
- non-ossifying fibroma
- giant cell tumor
- aneurysmal bone cyst
What benign tumors are commonly found in the diaphysis of bone?
- enchondroma
- fibrous dysplasia
What bones have the potential to develop benign cartilage tumor cells?
any bone formed by endochondral ossification (tubular bones)
Name 3 benign bone forming tumors
- osteoma
- osteoid osteoma
- osteoblastoma
Name 3 benign cartilage forming tumors
- osteochondroma
- chondroma
- chondroblastoma
What is the origin of giant cell tumors?
unknown origin (similar to macrophages)
Which of the following is a radiographic characteristic of an aggressive lesion?
A) non-invasive
B) short zone of transition
C) no periosteal disruption
D) cortical destruction
D
Which of the following is primarily osteoblastic and would result in a radiopaque appearance?
A) aneurysmal bone cyst
B) osteoma
C) fibrous cortical defect
D) simple bone cyst
B
Which of the following is most consistent with a non-aggressive lesion of bone?
A) laminated periosteal reaction
B) elevated ESR
C) motheaten osteolysis
D) narrow zone of transition
D
