Chapter 17 - Appendicular skeleton/bone tumours Flashcards
Best ancillary radiographic view to project the bicipital groove for changes associated with tenosynovitis
Cranioproximal/craniodistal view
Best ancillary radiographic view to project the trochlea of talus wihtout superposition of calcaneus
Flexed dorsoplantar view
IMPORTANT
Which are the 3 criteria used to determine whether a bone lesion is
aggressive?
How many of these criteria are needed to fulfill the definition of aggressiveness?
(1) type of periosteal reaction
(2) Cortical integrity
(3) Transition zone (distinctness of the boundary
between the bone lesion and the normal bone)
1, Importantly, whether a lesion is primarily radiolucent (osteolytic) or radiopaque (osteoproliferative) has no bearing on whether the lesion is aggressive.
Cortex destruction or effacement is always radiographically apparent independently of the projection? True or false
False, to be apparent radiographically, the region of destruction must be hit tangentially by the primary x-ray beam
What features of the following are related with agressive lesions?
- Geographic lysis
- Moth-eaten and permeative lysis
- Cortical expansion
- Uneven periosteal reaction
Uneven periosteal reaction
What is FALSE about periosteal reaction?
a. Commonly caused by elevation of the periosteum or regional hyperemia causing activation of bone-forming mesenchymal cells.
b. Irregular margin is the clue that the periosteal reaction is inactive
c. A smooth periosteal reaction does not mean that the lesion is not aggressive
d Only uneven periosteal reaction would be enough to identify an agressive lesion
b active, no inactive
active = irregular = agressive lesion
Where is usually evaluated the transition zone?
- Medullary cavity of the bone
Agressive or non-agressive?
low radiographic aggressiveness does mean low biologic aggressiveness? True or false
False
But, importantly, the absence of radiographic evidence of aggressiveness usually means no biologic aggressiveness.
the categorization of aggressiveness does not take into account whether the lesion is primarily productive or primarily destructive. True or false
True
agressive or not?
Yes, although neoplasia and infection are the two most important considerations for an aggressive bone lesion, there are many other clinical entities that result in an aggressive bone
lesion DAMNITV.
agressive or not agressive lesion?
A definitive distinction between neoplastic and infectious bone lesions is impossible by radiographic. True or false
True
However, the radiographic features of the bone lesion, such as the number of
bones involved and the location of the lesions within the bones, along with the signalment, history, and physical and laboratory findings can be used to prioritize the possible causes
Causes of agressive bone lesions (at least 4)
DAMNITV
1 degenerative
2 anomalous
3 metabolic
4 neoplastic
5 infectious [inflammatory, immune]
6 traumatic
7 vascular
Match the most likely diagnosis (generalizations):
1. Monostotic, anywhere, variable age
2. Monostotic, metaphyseal, older patients
3. Polyostotic, epiphyseal, young patients
4. Polyostotic, epiphyseal and metaphyseal, then duaphyseal, older patients
5. Polyostotic, metaphyseal or diaphyseal, young patients
- Primary bone tumour
- Hypertrophic osteopathy
- Osteochondrosis
- Bacterial osteomyelitis - traumatic
- Bacterial osteomyelitis - hematogeneous
Example of targeted viewing for proximal margin of the anconeal process in dogs at risk of having elbow dysplasia
UAP
- In dogs, the anconeal process should typically fuse with the rest of the ulna by 22 weeks/ 5 months/154 days
- In dogs, particularly large and rapidly growing breeds like German Shepherds, Labrador Retrievers, and Golden Retrievers, the anconeal process is a key area of interest in diagnosing elbow dysplasia.
Examples of targeted viewing for proximal margin of the medial ridge of the talus in dogs at risk for tarsal osteochondrosis
Large and giant breeds, like Labrador Retrievers and Rottweilers, are most affected
- Typically between 5 and 10 months old.
Examples of targeted viewing for distal radial and ulnar metaphysis in young dogs at risk for hypertrophic osteodystrophy (metaphyseal osteopathy)
- HOD primarily affects large and giant breed dogs between 2 and 8 months of age, with the highest incidence between 3 and 6 months.
- While HOD can affect any breed, certain breeds, like Weimaraners, Great Danes, German Shepherds, and Irish Setters, are more predisposed
Normal or abnormal? Rt forelimb lameness and pain on carpal palpation
normal cutback zone resulting
from remodeling of the distal ulna as it elongates. Normal finding in young.
- The “cutback zone” area in the metaphysis where the bone’s diameter is reduced to match the narrower diaphysis. This process, driven by osteoclasts on the periosteal surface and osteoblasts on the endosteal surface, is crucial for proper bone growth and shaping in young, growing animals.
-Contralateral same appearance lessens
the chance that this is a significant lesion
4 years old pitbull, most likely diagnosis
A primary bone tumor would be considered for any of these lesions independently but not in combination. Metastatic neoplasia could have this appearance. Diagnosis: coccidioidomycosis.
Most significant incidental factors associated with apendicular radiography in dogs and cats
a. Body condition
b. breed
c. congenital anomalies
d. Gender
b and c
Name the syndrome in feline patients
Lung-digit syndrome. Less common MODAL.
Protozoal bone infection mainly in south of US with mainly periosteal lesions, smooth to irregular.
Hepatozoonosis
What is false about bacterial bone infections:
a. it is more common than fungal bone infections
b. It is usually acquired by direct inoculation as from open fracture, bite wound or surgery.
c. Hematogeneous infection is relatively common
d. Hematogeneous infection particularly occurs in young potentially immune-compromised patients
c. Uncommmon
What is false about fungal osteomyelitis?
a. Fungal osteomyelitis can sometimes result in a monostotic
aggressive lesion in the metaphysis, as commonly
occurs with a primary bone tumor.
b. Generally of hematogenous origin
c. the southeast is typically an endemic region for blastomycosis and
coccidioidomycosis
d. All the above are true
c, southwest (occidioidomycosis.
Other radiographic abnormalities, such as lung lesions or mediastinal lymphadenopathy, may favor a fungal infection, but other testing is still necessary for a definitive diagnosis.
What is false about subungual lesions?
a. It is essentially impossible to differentiate between infectious
and neoplastic bone lesions in the digit by radiographic means.
b. The most common canine subungual tumors are squamous cell
carcinoma and melanoma.
c. Digital tumors typically involve a multiple digits
d. Metastasis of pulmonary tumors to multiple digits, termed the lung-digit syndrome, occurs
in cats
c, single digit
What is false about metastatic bone tumours?
a. General bone metastasis from sarcomas is more common than from carcinomas
b. Bone metastasis arise hematogeneously, which usually leads to a polyostotic distribution, either in the axial and/or appendicular skeleton
c. The lesion distribution is metaphyseal or diaphyseal through the nutrient foramen
d. Most common sites are in the axial skeleton, such as vertebrae and ribs, and the proximal extent of long bones.
a. from carcinomas is more common, dogs, mammary and lung cancers are a common source of bone metastasis
what is false about primary bone tumours?
a. Osteosarcoma is the most common and is usually single (monostotic) agressive lesion in the metaphysis.
b. Small peak incidence in dogs approx. 2 years and then larger peak later in adult life
c. In cats follows as well a bimodal distribution.
d. Common OA sites are away from the elbow and close to the stifle. Tumours in ths distal tibia are also relatively common.
c. No bimodal distribution in cats, typically occurs in older cats.
