Benign Bone Forming Tumors Flashcards
Osteomas are ____-growing
slow
What are osteomas comprised of?
dense cortical bone
What is the preferential location of osteomas?
skull:
- calvarial & mandibular
- sinonasal & orbital bone
- sinuses: frontal, maxillary, ethmoid, sphenoid, mastoid
What is a potential complication of an osteoma?
sinusitis if formed in sinus
causes sinus pain & pressure due to obstruction
Having multiple osteomas is implicated in what pathology?
Gardner syndrome
(a variant of familial adenomatous polyposis (fAPC), associated with extra-colonic features)
What is the radiographic appearance of an osteoma?
- densely blastic mass
- well-defined borders
Enostomas are ____-growing
slow
What are enostomas comprised of?
dense cortical bone
What is the preferential location of enostomas?
non-skull:
- medullary cavity
- long bone surfaces
Enostomas are also called ____ OR ____ of bone
- bone island
- hamartoma
Bone islands are comprised of ____ bone, located in ____ space
- dense cortical
- trabecular
What does “hamartoma” mean?
abnormal/disorganized growth comprised of the same tissue from which it grows
How would you differentiate an enostoma from blastic metastasis?
- ESR would be elevated if mets.
- bone scan shows “hot” areas of blastic activity if mets.
How does an enostoma appear on a bone scan and why?
appears normal because enostoma is comprised of normal tissue, just disorganized (no increase in blastic activity)
Are benign tumors considered aggressive or non-aggressive?
non-aggressive
What pattern of destruction is seen in osteomas and enostomas?
blastic
What is the treatment for osteomas and enostomas?
- clinical significance usually minimal
- surgical removal if in sensitive location
The center of an osteoid osteoma is called a ____
nidus
What is a nidus comprised of?
irregular trabeculae of woven bone (osteoid) within a vascular fibrous stroma containing osteoblasts & osteoclasts
What part of a nidus may be ossified?
trabeculae in center (more mature)
What age group is primarily affected by osteoid osteomas?
5-35 years
(most in teens)
What bones are capable of forming an osteoid osteoma?
any bone that formed via endochondral ossification
What is the preferential location of osteoid osteoma?
- femur or tibia (50%)
(10% in spine) - typically in cortical bone, may arise in medullary cavity
How large is a typical nidus?
<1 cm
How does an osteoid osteoma appear radiographically?
radiolucent lesion (nidus) surrounded by sclerotic bone
What type of periosteal reaction is seen in an osteoid osteoma?
solid
What pathology is associated with high levels of PGE2 in the area of the lesion?
Osteoid osteoma
How would a patient with an osteoid osteoma present clinically?
- insidious onset
- pain at night (fewer distractions; can behave similar to fatigue Fx in adolescents)
- pain relieved by aspirin/NSAIDs
What pathology responds to aspirin/NSAIDs and why?
Osteoid Osteoma
- PGE2 released causes vasodilation of vascular components in stroma
- aspirin/NSAIDs cause vasoconstriction
What type of periosteal reaction would occur in a fatigue fracture?
solid
How might you differentiate a fatigue fracture from osteoid osteoma if unsure about an x-ray?
CT scan -> gives good bony definition, can see nidus clearly
What is the natural history of an osteoid osteoma?
- will go away with time (~2 yrs)
- pain will persist (6-8/10)
How is an osteoid osteoma treated?
removal of nidus via En Bloc excision
What is an osteoblastoma comprised of?
(similar to osteoid osteoma)
osteoblasts lay down osteoid
What is the preferential location of osteoblastoma?
spine: laminae & pedicles (post. elements)
How large is a typical osteoblastoma?
> 2cm diameter (progressive enlargement)
How does osteoblastoma appear radiographically?
radiolucent lesion without sclerotic reaction
What pattern of destruction is seen in osteoblastoma?
geographic lytic
What type of periosteal reaction is seen in osteoblastoma?
none
Osteoblastomas release ____ causing…
prostaglandins causing pain (less than osteoid osteoma)
How does osteoblastoma respond to aspirin?
pain unresponsive to aspirin (takes much larger dose due to ^size of lesion)
How is an osteoblastoma treated?
(similar to osteoid osteoma)
- wide/en bloc excision via curette (not preferred)
- radiofrequency ablation -> electric probe inserted to liquify tumor (“microwaves” tumor)
If an osteoma is symptomatic, what is the most likely symptom?
A) “my hat doesn’t fit anymore”
B) visual disturbance
C) sinusitis
D) headaches
C
