14 - Bone IV Flashcards
1
Q
Proliferative (tumorous) lesions descriptive terms (5)
A
- Exostosis
- Osteophyte
- Enthesophyte
- Enostosis
- Hyperostosis
2
Q
Exostosis
A
- Benign bony growth projecting outward from the outer surface of a bone
- *nodular growth
3
Q
Osteophyte
A
- Another term for exostosis
- *describe small bony outgrowth at the PERIPHERY of a joint
o Usually associated with degenerative joint disease
4
Q
Enthesophyte
A
- Small exostosis at site of attachment of a ligament, tendon, or joint capsul
- Ex. an enthesis
5
Q
Enostosis
A
- Benign bony growth within the medullary cavity of a bone
6
Q
Hyperostosis
A
- Indicate that the dimension of bone has increased
o Ex. thickened along one or more periosteal surfaces - More-than-less uniform thickening of bone along periosteal surface rather than nodular growths
7
Q
What are some specific diseases of proliferative lesions?
A
- Hypertrophic osteopathy
- Osteochondromas and multiple cartilaginous exostoses(MCE)
- Craniomandibular osteopathy: ‘lion jaw’
- Calvarial hyperostotic syndrome
- Deforming cervical spondylosis
8
Q
Hypertrophic osteopathy
A
- Older dogs and other mammals
- Periosteal new bone over distal limbs (‘fuzzy’)
- Always forelimbs, sometimes hindlimbs
- *always concurrent disease
o Usually an intrathoracic neoplasm OR inflammation
o Uncertain pathogenies
o If clear intrathoracic disease=this lesion should clear up
9
Q
Osteochondromas and MCE (multiple cartilaginous exostoses)
A
- People, horses, dogs (cats)
- Inherited disease
- Masses of trabecular bone with cartilaginous cap projection from metaphyseal areas of endochondral bones
o Appear early in life and increase in size through endochondral ossification of the cartilaginous cap. STOP growing at skeletal maturity - *benign
o Space occupying=can be annoying or dramatic effects (ex. compress SC)
10
Q
Craniomandibular osteopathy: ‘lion jaw’
A
- Heritable in TERRIERS and other dogs but rarely
- Unknown pathogenesis
- Progressive periosteal new bone over the mandible and other bones of head
o By itself is not a problem, but eventually can’t open mouth=can’t eat
11
Q
Calvarial hyperostotic syndrome
A
- YOUNG, bullmastiff dogs
- Unknown cause
- Progressive, asymmetric cortical thickening of bones of skull cap
o Ex. frontal, parietal, temporal and occipital bones
12
Q
Deforming cervical spondylosis
A
- ADULT CATS caused by prolonged exposure to excess Vitamin A
o Due to unconventional diet (ex. beef liver) - Formation of extensive exostoses over dorsal and lateral aspects of cervical vertebrae often leading to ANKYLOSES
13
Q
What can be affected in severe cases of deforming cervical spondylosis?
A
- Occipital bone
- Cranial thoracic vertebrae
- Sternum
- Proximal forelimbs
- *if intervertebral foramina are reduced in size=can be compression and degeneration of associated nerves
14
Q
Ankylosis
A
- Fusion of bones across a joint
- Fixation of a joint by disease or surgery
15
Q
Neoplastic disorders of bone
A
- Primary or secondary
o Benign or malignant
16
Q
Where do primary neoplasms of bone typically arise from?
A
- 85% from bone
- 15% from cartilage
- Other: may arise from fibrous tissue, blood vessels, adipose and etcetera
17
Q
What are some examples of benign primary neoplasms of bone?
A
- Osteomas
- Chondromas
- Ossifying fibromas
18
Q
Osteomas
A
- Uncommon
- Grow slowly, but progressively by intramembranous ossification
- Usually arise from bones of the HEAD
- Composed of well-differentiated trabecular bone
19
Q
Chondromas
A
- Uncommon
- Slow growing neoplasms of HYALINE CARTILAGE
o Usually arise from bones of the head
20
Q
Ossifying fibromas
A
- Uncommon
- Large masses on mandible or maxilla of horses and cattle
- Well-differentiated fibrous tissue that contains SCATTERED SPICULES of woven bone
21
Q
With time what happens with ossifying fibromas?
A
- Greater proportion of mass becomes ossified and resembles an OSTEMOA
22
Q
What are some examples of malignant primary neoplasms of bone?
A
- Osteosarcoma
- Chondrosarcomas
- Fibrosarcomas
- Hemangiosarcomas
- Giant cell tumor of bone
- Multilobular tumor of bone
- Maxillary fibrosarcomas
- Bone surface neoplasms
23
Q
Osteosarcoma
A
- Relatively common
- Rapidly growing, malignant tumors in which neoplastic cells form osteoid or bone
- Can cause destruction of preexisting bone
- *most commonly in LONG bones of limbs
24
Q
What are osteosarcomas characterized by?
A
- Aggressive local invasion and early metastasis
- *not invasion of joint spaces
25
Q
Where are osteosarcomas usually found in large, giant breed dogs?
A
- Appendicular skeleton
o Front limbs TWICE as often as hind limbs (‘always away from elbow, and toward the knee’
26
Q
Where are osteosarcomas usually found in small breed dogs?
A
- Axial skeleton
27
Q
Osteosarcoma and metastasis ‘stats’
A
- 15% have it at diagnosis
- 90% dies of metastatic disease within 1 year
28
Q
Chondrosarcomas
A
- Not common
- Grow slowly
- Cause local destruction of bone, but metastasize late
- *defining features=malignant cells produce cartilaginous ECM, but NEVER osteoid or bone
29
Q
Fibrosarcomas
A
- Malignant tumours composed of fibroblasts and connective tissue they produce
- Those arising in bone can cause destruction of bone
30
Q
Hemangiosarcomas
A
- Malignant tumours of vascular endothelium
o In this context: arises from within a bone
31
Q
Giant cell tumour of bone
A
- Malignant neoplasm of bone marrow stomal cells
- Many osteoclasts in the lesion, but they are NOT neoplastic cells
- (used to be called osteoclastomas, but the osteoclasts are NOT neoplastic)
32
Q
Multilobular tumor of bone (or canine multilobular osteochondrosarcom)
A
- Uncommon
- Slow growing
- Often malignant neoplasma of skull bones of dog
- *tends to be locally invasive
o Typically leads to euthanasia of affected dogs - Metastasis is not common
33
Q
Maxillary fibrosarcomas
A
- ONLY in DOGS
- Benign histologic appearance, but are MALIGNANT
o Mostly invasive, sometimes metastatic - Can also arise in other bones of the head
34
Q
Bone surface neoplasms
A
- Arise from periosteum
- Malignant, but slower growing and less aggressive then corresponding neoplasms originating within bone
35
Q
What are some types of bone surface neoplasms?
A
- Periosteal osteosarcoma
- Periosteal chondrosarcoma
- Periosteal fibrosarcoma
- Parosteal osteosarcoma
36
Q
What is the difference between periosteal and parosteal sarcoma?
A
- Periosteal: invade underlying cortex
- Parosteal: do NOT invade underlying cortex
o Or if do, it is much later in the disease
37
Q
Secondary neoplasm of bone
A
- Malignant
- Usually spread via circulation and begin to grow within bones
o Due to vascular nature of bone marrow - *some result in more bone lysis than formation, while others are the opposite
- *carcinomas are reported to metastasize to bone more frequently than sarcomas
38
Q
What can metastatic neoplasms in bone be associated with?
A
- Pain
- Lysis of bone
- Pathologic fracture
- New bone formation
39
Q
What is the most common type of bone marrow neoplasm to affect bone?
A
- Multiple myeloma OR plasma cell myeloma
40
Q
Bone cysts and cyst-like lesions
A
- Rare, discrete cavities within a bone that may distort the CORTEX
o Cavity usually filled with fluid or soft tissue - *’not cysts’: have no epithelial lining
- *may reduce bone strength and cause lameness
41
Q
Fibrous dysplasia
A
- Uncommon lesion in YOUNG animals
o Likely a developmental defect - Expanding mass of fibro-osseous tissue that results in DISTORTION and WEAKENING of the cortex of the affected bone
