Age / Sex : 47 / F

Age / Sex :

18 month / F

Chief complaint : Left lower leg bowing
deformity

1) What is your impression?



Two weeks later, you can see the final diagnosis with a brief discussion of
this case.



* Send Application Answers to In Sook Lee, MD ([email protected])



Courtesy : Yoo Hye Jin, Seoul National University Hospital

Focal fibrocartilaginous dysplasia of tibia

Discussion

Findings:

 Oblique clearly defined bony defect with
marginal sclerosis in the medial metaphysis of the proximal tibia

Differential Diagnosis:

 Blount’s disease

Diagnosis:
 

Focal
fibrocartilaginous dysplasia of tibia

Discussion:

 An uncommon benign
condition that causes bowing deformity of long bones in young children
(unilateral)

1.
Radiologic features - pathognomic

•       Oblique cleared defined bony defect
with marginal sclerosis in the medial metaphysis of the long bone

•       Fibrocartilage and tendon like
tissue -> low SI at MRI

2. Histology

•       Fibrocartilage and fibrous
tendon-like tissue

•       Bell and colleagues in their
original paper suggested that the mesenchymal anlage at the tendon insertion
failed to differentiate normally and persisted as a focus of fibrocartilage

3. Site : proximal tibia > femur, ulna, humerus, radius, phalanx

4. Clinical
onset : between 3 and 18 month

5. Prognosis
:  Spontaneous resolution, 1 to 4 years

6. DDx with
Blount’s disease : bilateral, older age, male, African

References:

Radiology Case. 2009 Sep; 3(9):14-17

Skeletal
Radiology 1994 23:333-335