GCT, Osteochondroma, & Hemangioma Flashcards
A giant cell tumor (GCT) is also called ____
Osteoclastoma
What are giant cell tumors comprised of?
Giant cells = osteoclasts
What age group is primarily affected by osteoclastomas?
20-40 years
Most giant cell tumors are (benign/malignant)
Benign (80%)
The term, ____ refers to giant cell tumors being born malignant, rather than undergoing malignant degeneration.
Quasimalignant
What is the typical pattern of destruction of a giant cell tumor?
Geographic lytic
What is the term for a tumor that extends into the epiphysis of a bone?
Subarticular extension
(Arise in metaphysis, extend into epiphysis)
How would a patient with a giant cell tumor present clinically?
- age 20-40 yrs
- localized pain & aching
- joint pain (not reproducible) + decreased ROM
How would a giant cell tumor present differently from an enchondroma?
Painful
(Enchondroma generally asymptomatic)
What are the radiographic characteristics of a giant cell tumor?
- geographic lytic lesion
- narrow/short ZoT
- IF expansile, bone surrounding lesion is very thin
- frequently multiloculated
Which of the following is NOT a bone forming tumor?
A) enchondroma
B) osteoid osteoma
C) osteochondroma
D) osteoma
A
Which benign lesion is most likely to have pain?
A) osteoma
B) enostoma
C) osteoid osteoma
D) osteochondroma
C
Giant cell tumors spare ____ bone
subchondral (subarticular) bone
How can you tell the difference between a benign and malignant giant cell tumor?
appear the same, need a biopsy to tell
What are the imaging features of a giant cell tumor?
- geographic lytic
- multiloculated & septated
- begins in metaphysis
- subarticular extension
- expansile
- eccentric
- absence of corticated border
What radiographic is characteristic of a giant cell tumor?
subarticular extension
(NOT pathognomonic)
What mnemonic is used for differential diagnoses of a non-aggressive lesion in the posterior elements of the spine?
Alphabet soup:
ABC / GCT / OB / OC / OO
An osteochondroma is also called ____
exostosis
What age group is primarily affected by osteochondroma?
skeletally immature (<20), but keep it for the rest of life
What is the most common benign skeletal tumor?
osteochondroma
What is the chance of malignant transformation of an osteochondroma?
<1%
What are the 2 types of osteochondroma?
- pedunculated
- sessile
What signs and symptoms would suggest malignant transformation of an osteochondroma? What follow-up would you suggest?
becomes painful w/ rapid growth
MRI or CT
What are the preferential locations of osteochondromas?
tubular bones + post. elements of spine (any endochondral ossified bones)
- femur
- humerus
- tibia
- pelvis
- ribs
- scapula
What is the name for the multiple form of osteochondroma?
Hereditary Multiple Exostosis (HME)
Hereditary Multiple Exostosis is also called ____
osteochondromatosis
What is the chance of malignant transformation of osteochondromatosis?
25%
What is a major difference between the solitary and multiple forms of osteochondroma in terms of possible outcomes?
- solitary: <1% chance of malignant transformation
- multiple: up to 25% undergo malignant transformation
If an osteochondroma undergoes malignant degeneration, what will it transform into?
- chondrosarcoma (most likely)
- osteosarcoma
Describe the appearance of a pedunculated osteochondroma
- thin, elongated bony stalk
- cartilage cap (may be calcified)
- should not be thicker than 10mm
- metaphyseal
- continuous cortex & medullary space
- projects away from joint
- lucent when en face
Describe the appearance of a sessile osteochondroma
- don’t often have cartilaginous cap
- broad-based metaphysis
- lucent when en face
At what point is a pedunculated osteochondroma considered to undergo malignant transformation?
when cartilage cap >2cm thickness
(use MRI to evaluate)
What is the preferential location of osteochondromas?
- knee is common
- pelvis, scapula, ribs
- metaphysis near growth plate of endochondral bones only
2 or more osteochondroma lesions is termed ____
Hereditary Multiple Exostosis (HME)
How may a patient with a sessile osteochondroma present clinically?
Generally painless (non-tender), non-mobile, potentially palpable lump
Potential complications:
- tendinosis/bursitis
- neurovascular bundle compromise
- malignant transformation
How would a patient with pedunculated osteochondroma present clinically?
Generally painless (non-tender), non-mobile, potentially palpable lumps
Potential complications:
- pathological fracture
- tendinosis/bursitis
- neurovascular bundle compromise
- malignant transformation
How would a patient with Hereditary Multiple Exostosis present clinically?
- begin forming both sessile & pedunculated osteochondromas 20-10 years old
- commonly deformed metaphysis (Madelung-like deformity, dwarfism)
- limited ROM
- family Hx
(in addition to SSx of solitary osteochondroma)
What is the term for the radiographic appearance of a sessile osteochondroma on the medial aspect of the femoral neck, commonly seen in patients with HME?
Brahma bull appearance
What are your next steps for a patient with an osteochondroma with a cartilage cap that is 15mm in thickness?
MRI w/ contrast
(for 10-20mm thickness)
What is a hemangioma?
slow-growing, solitary vascular neoplasm
What are the 2 types of hemangiomas?
- cavernous
- capillary
Where do cavernous hemangiomas occur?
spine
skull
Where do capillary hemangiomas occur?
- ribs
- pelvis
- metaphysis of long bones
What is the most common benign bone tumor of the spine?
hemangioma
What age group is primarily affected by hemangiomas?
40+ yrs
What is the clinical presentation of a hemangioma?
- most are asymptomatic, incidental finding (not significant)
- expansion can cause Sx of impingement & stenosis (rare)
Where do hemangiomas most commonly occur?
75% in spine & skull
- lower thoracic & upper lumbar (TL)
- vertebral arch (10-15%)
What radiographic sign is associated with hemangioma?
corduroy cloth/jail bar appearance
(vertically striated vertebra)
At what point is corduroy cloth or jail bar appearance visible radiographically?
> 50% of vertebral body involved
What causes corduroy cloth or jail bar appearance?
Wolf’s law: resorption of horizontal trabeculae, ^vertical trabeculae
How does a hemangioma appear on MRI?
bright on both T1 and T2
(fat surrounds blood vessels)
How does a hemangioma appear on CT?
polka dotted appearance
How does a hemangioma in the skull appear radiographically?
geographic lytic lesion w/ matrix calcification:
- sand dollar
- sunburst or spoked-wheel
What 2 conditions are on your list of differential diagnoses for a hemangioma?
- paget Dz
- osteoporosis
How are soft tissue hemangiomas visualized radiographically?
round, well-formed phleboliths
A 35 year old patient with a history of a single sessile osteochondroma arising from the medial aspect of the distal femur presents with pain immediately adjacent to that site. Light touch is intact, muscle testing of the leg is 5/5, and pulses are strong. What is the most likely explanation for why there is pain?
A) neurovascular bundle impingement
B) fracture
C) malignant degeneration
D) tendinosis/bursitis
D
What DDx mnemonic is used for this lesion?
FEGNOMASHIC
20 year old female with left wrist pain. Give 3 differentials in order from most to least likely.
(FEGNOMASHIC)
1. GCT (20-40, pain, subarticular sparing)
2. ABC (<20, pain, metaphyseal/epiphyseal)
3. Chondroblastoma (10-25, pain, epiphyseal)
What is the diagnosis?
Hemangioma
What sign is this?
Polka dot sign (hemangioma on CT)
What imaging modality is this?
T2 MRI
What is the diagnosis? What bone is involved?
Sessile osteochondroma of medial fibula
What is the diagnosis?
Sessile osteochondroma
What is the diagnosis?
Hereditary Multiple Exostoses (HME)
What is the diagnosis?
Pedunculated osteochondroma
What is the likely diagnosis? What radiographic feature supports your diagnosis?
GCT - subarticular extension
Give 4 reasons these may become painful.
(Osteochondromas)
- tendinosis/bursitis
- neurovascular bundle compromise
- malignant transformation
- fracture (Pedunculated only)
What is the chance of malignant transformation?
(Osteochondromatosis/HME)
25%
What is the name given to the radiographic appearance of the femoral necks?
Brahma bull appearance
(osteochondromatosis)
What imaging finding indicates malignant degeneration of this condition? What would it degenerate to?
(Dx = Osteochondromatosis)
Cartilage cap thicker than 2cm
—> chondrosarcoma
What is the diagnosis? What is the radiographic sign?
Hemangioma
Corduroy cloth (jail bar) sign
What is the radiographic sign? What is the diagnosis?
Sand dollar appearance
Hemangioma
