Radio - Neoplasia / Infection Flashcards
Bone production takes how long before significant mineral olpacity can be seen?
10-14 days
What can be seen on radiographs after 5-7 days?
Decreased olpacity due to significant mineral loss from bone lysis/reabsorption
Benign changes
Chronic, degenerative, slow
Aggressive changes
Active, ongoing, rapid
Most important component to assessing if a lesion is aggressive
Component productive or lytic - presence of lytic automatic aggressive
Pattern of bone lysis
Presence of cortical destruction
Zone of transition
Periosteal reaction/proliforation
Active vs inactive
Immature vs chronic
Short zone of transition
Walled off disease process
Edge of lesion is well demarkated
Sclerotic border indicates a benign process
Long zone of transition
Body cannot contain process
No distinct boarders
What type of bone tumor is less common?
Benign bone cyst
Stages of bone lysis
Permeative
Moth-eaten
Geographic
Appearance of permeative lysis stage
Pin point areas
Aggressive
Moth eaten pattens of lysis
Moderate sized area
Aggressive
Geographic patterns of lysis
Large area of lysis
Aggressive or benign
Periosteal layers
Outer fibrous layer
Inner Cambrian layer (bone production)
Stimulation of periosteum
Produce bone towards the cortex
Solid to process = benign
Pocketed appearance = aggressive
Periosteal reaction types
Solid
Lamellar
Interrupted
Complex
Solid reaction type
Smooth or palisading
Lamellar reaction
Intermediate layered appearance
Indicates cyclic growth process
Interrupted reaction
Spiculated appearance
Long thin spicules indicate more aggressive process than shorter thicker spicules
Complex reaction
Sunburst or amorphous
Sunburst reactions
Spicules radiate from a central point indicating a focal point where a tumor has broken from the cortex
Amorphous reaction
Bone is formed disorganized
Process may destroy spicules of bone as they form
Classifications for reactions
Level of aggression
Activity level
Duration
Codmans triangle
Solid periosteal reaction seen at the edge of an aggressive reaction
Activity level can be determined by what feature
How clear the edges of a lesion are, can they be outlined w a pencil or no?
Olpacities role in reactions
The older the lesion the more opaque or bone like it becomes
Primary bone tumors occur is which groups
Large breed dogs
As young as 6m, typical 7Y
More common in males
Typical features of primary bone tumors
Aggressive characteristics
Mono static
Rarely crosses joints or breeches other bones
Metaphyseal location
Metaphyseal location w bone tumors
Away from elbow (prox hum & distal rad)
Toward the stifle (prox tibia & distal femur)
Distal tibial - proximal diaphysis
Largest percent of bone tumor types
75% osteosarcoma
Other possible tumor diagnosis
Chondrosarcoma
Fibrosarcoma
Hemangiosarcoma
Metastatic bone disease
Poly or monostotic
Diaphysis, flat bones
Aggressive characteristics
Neoplasms that metastasize to bone
neoplasms that commonly metastasize to bone
Carcinoma (mammary, lung, liver, thyroid, urinary, prostate)
Osteosarcoma - systematic disease 14% have full body met
Fungal osteomyelitis
Aggressive characteristics
Periosteal reaction is semi aggressive
Lysis may extend through cortex
Adjacent medullary sclerosis
Common places for histoplasmosis
East US
Spread to bone is rare
Blastomycosis
Middle Atlantic, SE sates
30% of cases have bone involvement
Most common fungal osteomyelitis
Coccidoidomycosis (coccidioides immitus)
Mono static
Dia or metaphysis
Predominant proliferation
Hilar lymphadenopathy
Bacterial osteomyelitis juveniles
Epiphysis and metaphysis of long bones in animals w decreased immunity
Bacterial osteomyelitis in adults
Often at site or injury or surgery, Will not occur spontaneously
Radiograph appearance for bacterial osteomyelitis
Earliest stages = soft tissue swelling
Reaction is typically solid, extends along shaft of diaphysis
