Case 2: Hair on my Chinny, Chin Chin

Superimposed lower incisors

Letter A is positioned over what anatomic structure?

d. All of the above

When evaluating bone margins, what are the questions you should be asking yourself?

a. Is the margin in question smooth or irregular?

b. Is the margin in question continuous or disrupted?

c. Is the margin in question thinner than normal?

d. All of the above

As Low As Reasonably Achievable

What does ALARA stand for?

Premaxilla

Letter C is pointing to what bone (the bone where the upper incisors live)?

False (lesion does not extend into the cortex and has a distinct transition from abnormal bone to normal bone)

This is an example of an aggressive osseous lesion.

TRUE OR FALSE

xx

Just so you have an idea of what the horse looked like from the outside.. firm, not easily moved mass on horse's jaw

Equine Lateral, oblique and DV projections are available for review.

Describe the study you are seeing here

Patient positioning is adequate for interpretation.

Study technique is adequate for interpretation

Describe patient positioning and technique

An expansile, mixed lytic and proliferative mass with rough, spiculated and irregular margins extends the entire left interalveolar space from the lower incisors to the first premolar. The cortical margins of the mandible in the region of the mass are not clearly identified. There is an ill-defined, wide zone of transition between normal and abnormal bone. Mild soft tissue thickening adjacent to the mass is present.

note: the "rough spiculated irregular margins" is defining the periosteal reaction

Describe your findings (roentgen signs)

Aggressive, monostotic mass in the interalveolar space is most consistent with a primary bone neoplasia. Given the location of the mass (mandibular) osteosarcoma is considered likely, but other primary bone tumor types like fibrosarcoma cannot be ruled out. Other differential considerations also include neoplasia of dental origin or squamous cell sarcoma.

Describe Conclusions: Give your radiographic diagnosis and list possible differential diagnoses for all your findings

Biopsy is required for definitive diagnosis. Alternatively, a fine needle aspirate could also be tried in order to get a diagnostic sample.

Describe Next Steps: Are there any additional imaging suggestions that would help clarify your findings? Are there critical next steps to take from a stabilization/management/treatment plan standpoint?

Interalveolar space between incisors and premolars

What is the location of this mass in this horse?

1. what does cortex look like

2. what is happening at transition from abnormal bone to normal bone (is there a clear demarcation?)

3. what is the periosteal reaction like

= only need ONE of these things for a bone lesion to be considered aggressive

What 3 questions help you to determine if this is an aggressive or nonaggressive lesion?

Spiculated, Sunburst, Irregular

These are the several types of periosteal reactions that can occur with bone lesions. Which of these periosteal reactions would be characterized as more aggressive because the lesion is growing SO fast it will not be "regular"?

Spiculated = more aggressive reaction

How would you describe this periosteal reaction pattern?

There is only one BONE lesion

What does "monoastotic" mean?

Osteosarcoma

note: osteosarcoma is RARE in the horse, but if it IS in horses, it will be in the mandible

Given the location of a bony lesion mass in the mandible of a horse, which primary neoplasia is most likely?

False

Osteosarcoma is a very common diagnosis in equine patients

TRUE OR FALSE

ALL OF THE ABOVE

a. cortical destruction with a short zone of transition

b. long zone of transition with a lamellar periosteal reaction

c. cortical disruption, a long zone of transition and an irregular periosteal reaction

Which factors must be present in order to classify an osseous lesion aggressive? (select all that apply)

a. cortical destruction with a short zone of transition

b. long zone of transition with a lamellar periosteal reaction

c. cortical disruption, a long zone of transition and an irregular periosteal reaction

False

If a bony lesion appears aggressive on the radiographs, it will also likely be very aggressive biologically.

TRUE OR FALSE

True

If a lesion does not have any characteristics of aggressiveness, it is likely that the lesion is not biologically aggressive.

TRUE OR FALSE

c. Lysis and/or proliferation alone are not adequate to classify

Which is more aggressive?

a. lytic lesion

b. a proliferative lesion

c. Lysis and/or proliferation alone are not adequate to classify

FALSE: in this case, you can see an ungloved finger on the left side of the image

In the DV view in this case, the technician assisting with taking this radiograph was following ALARA principles.

TRUE OR FALSE

False

It is very easy to distinguish bone neoplasia from osteomyelitis by just looking at the radiographs.

TRUE OR FALSE

First Premolar

What is A?

Interalveolar space

What is B?

403

What is C?

401

What is D?

302

What is E?

Upper premolars

What is A?

Lower premolars

What is B?

Palatine bone

What is C?

Superimposed upper incisors

What is D?

Superimposed lower incisors

What is E?