(2) Enchondroma & Chondroblastoma

Question 1

What are enchondromas comprised of?

Answer 1

hyaline cartilage

Question 2

What population is primarily affected by enchondromas?

Answer 2

10-30 years (<20), keep for life

Question 3

Enchondromas form in bones of ____ ossification.

Answer 3

endochondral

Question 4

What is the preferential location of enchondromas?

Answer 4

• medullary long bone
• hands & feet

Question 5

If an enchondroma undergoes malignant degeneration, what will it turn into?

Answer 5

chondrosarcoma

Question 6

What is the chance of malignant transformation in a solitary enchondroma?

Answer 6

<1%

Question 7

Multiple enchondromas are referred to as ____

Answer 7

Ollier Disease
(has possible hereditary component)

Question 8

What is the chance of malignant transformation in Ollier Disease?

Answer 8

25%

Question 9

Multiple enchondromas plus soft tissue hemangiomas are referred to as ____

Answer 9

Mafucci Syndrome
(rare)

Question 10

Ollier Disease plus soft tissue hemangiomas are referred to as ____

Answer 10

Mafucci Syndrome
(rare)

Question 11

What is the chance of malignant transformation in Mafucci Syndrome?

Answer 11

50%

Question 12

What are the multiple forms of enchondroma called?

Answer 12

• Ollier disease
• Mafucci syndrome

Question 13

What is the most common benign tumor of the hands and feet?

Answer 13

Enchondroma

Question 14

How would a patient with an enchondroma present clinically?

Answer 14

• usually asymptomatic (incidental finding)
• Patho Fx (painful)
• No Fx + pain = possible malignancy

Question 15

How would you differentiate between an enchondroma and a chondrosarcoma?

Answer 15

use MRI with contrast (inject with gadolinium) to highlight vascular structures
- enchondroma shows up normal
- chondrosarcoma shows high contrast (^angiogenesis)

Question 16

What are the radiographic characteristics of an enchondroma?

Answer 16

• geographic lytic lesion w/ or w/out sclerotic border
• narrow/short ZoT
• 50% have stippled calcification
• intact & thinned cortex (expansile)
• endosteal scalloping

Question 17

How does the matrix of an enchondroma in a long tubular bone compare to one in the hands and feet?

Answer 17

less geographic lytic, more stippled calcification (DDx: ICE)

Question 18

What is endosteal scalloping?

Answer 18

curvilinear/ridged edges of inside surface of bone (endosteum) due to pressure erosion

Question 19

How would a patient with Ollier Disease present clinically?

Answer 19

• manifests <10yrs old
• severe skeletal deformity
• shortened bones (dwarfing)
• patho Fx

Question 20

What type of matrix calcification is seen in Ollier disease?

Answer 20

stippled calcification (hyaline cartilage)

Question 21

What is the pattern of destruction in Ollier disease?

Answer 21

geographic lytic

Question 22

Small, round lumps of calcium that form in a person’s veins, which may show up as white spots radiographically are called ____

Answer 22

phleboliths

Question 23

What are the radiographic characteristics of Mafucci syndrome?

Answer 23

• multiple geographic lytic lesions
• phleboliths outside of pelvic basin

Question 24

Multiple phleboliths outside of the pelvic basin indicates ____

Answer 24

hemangiomas

Question 25

How would a patient with Mafucci syndrome present clinically?

Answer 25

- young manifestation - shortened bones - dense, purple-coloured skin - bone deformities - patho Fx

Question 26

What is your list of differential diagnoses for stippled calcification in the medullary canal of a tubular bone in a patient under 40 years old?

Answer 26

1. Enchondroma 2. Chondrosarcoma 3. Infarct

Question 27

What is your list of differential diagnoses for stippled calcification in the medullary canal of a tubular bone in a patient over 40 years old?

Answer 27

1. Chondrosarcoma 2. Enchondroma 3. Infarct

Question 28

What follow-up would you order to determine a differential diagnosis for stippled calcification in the medullary canal of a tubular bone?

Answer 28

MRI w/ contrast (NOT a biopsy, avoid mets)

Question 29

What is another name for Ollier disease?

Answer 29

enchondromatosis

Question 30

What is the preferential location of chondroblastomas?

Answer 30

- epiphyses (articular ends) & apophyses - endochondral bones - 90% medullary, 10% cortical

Question 31

What age group is primarily affected by chondroblastomas?

Answer 31

10-25 years (prior to closure of epiphyses)

Question 32

How would a patient with a chondroblastoma present clinically?

Answer 32

joint pain that is difficult to recreate with ortho tests (bone pain, not mechanical)

Question 33

What are the radiographic characteristics of chondroblastomas?

Answer 33

- geographic lytic lesion in epiphyseal region (slow-growing, well-defined borders) - 3-6cm circular lesion - internal calcification (50%)

Question 34

What is your list of differential diagnoses for a bubbly lytic lesion involving the epiphysis or metaepiphysis of a young patient?

Answer 34

1. ABC 2. GCT 3. Brodie abscess

Question 35

What type of matrix calcification would be seen in a chondroblastoma?

Answer 35

stippled

Question 36

What is the most common tumor to cross an open growth plate?

Answer 36

ABC (starts in metaphysis)

Question 37

What is the second most common tumor to cross an open growth plate?

Answer 37

chondroblastoma (starts in epiphysis)

Question 38

What imaging result gives an indirect indication that a chondroblastoma is painful?

Answer 38

STIR MRI for edema in marrow (halo of edema)

Question 39

What is the most likely diagnosis?

Answer 39

Enchondroma

Question 40

50 year old patient. What is your list of differentials in order from most to least likely?

Answer 40

(Stippled - ICE) 1. Chondrosarcoma 2. Enchondroma 3. Infarct

Question 41

What is the diagnosis?

Answer 41

Mafucci syndrome

Question 42

What is the most likely diagnosis?

Answer 42

Enchondroma

Question 43

What is the most likely diagnosis?

Answer 43

Enchondroma

Question 44

What is the diagnosis?

Answer 44

Mafucci syndrome

Question 45

Painful knee. There are 2 diagnoses present. Give both in order of clinical significance.

Answer 45

1. Chondroblastoma (epiphyseal, kid) 2. Bipartite patella