Weekly Case

Title : Case 596

Age / Sex : 0 / F


no clinical information (including age, sex, and chief complaint)

What is your impression?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).

Courtesy:  Dong-Ho, Ha, 
Dong-A university Hospital



Discussion


Answer: lipomyelocele


 


Findings:


MRI



  1. Fat signal intensity mass within the spinal canal


Fatty mass is continuous with the adjacdent subcutaneous fat



  1. Disruption of posterior spinal elements, but intact overlying skin

  2. Lipoma placode interface with low signal intensity is within the spinal canal.


 


Differential Diagnosis:


Closed spinal dyraphism


Congenital spinal lipomatous malformations



  1. Lipomyelocele

  2. lipomyelomeningocele


 


Diagnosis: 


lipomyelocele


 


Discussion:


Congenital malformations of spine and spinal cord are collectively termed as spinal dysraphism. On the basis of presence or absence of overlying skin covering, spinal dysraphism is divided into open and closed types. In an open spinal dysraphism, there is a defect in the overlying skin, and the neural tissue is exposed to the environment. In a closed spinal dysraphism, the neural tissue is covered by skin.


Closed spinal dysraphism CSD can be further divided based on the presence or absence of associated subcutaneous mass.


Closed spinal dysraphisms



  1. With subcutaneous mass

  2. Lipomyelomeningocele

  3. Lipomyelocele

  4. Terminal myelocystocele

  5. Meningocele

  6. Myelocystocele

  7. Without subcutaneous mass

  8. Simple dysraphic states

  9. Intradural lipoma

  10. Filar lipoma

  11. Tight filum terminale

  12. Persistent terminal ventricle

  13. Dermal sinus

  14. Complex dysraphic states

  15. Dorsal enteric fistula

  16. Neuroenteric cyst

  17. Diastematomyelia

  18. Caudal agenesis

  19. Segmental spinal dysgenesis


 


Lipomyeloceles and lipomyelomeningoceles is a spinal canal lipoma with deect and is a kind of closed spinal dysraphism with subcutaneous mass. These abnormalities result from defective primary neurulation where there is premature focal disjunction of cutaneous ectoderm and neuroectoderm allowing mesenchyme to enter the neural tube. This mesenchyme later forms the lipomatous tissue for unknown reasons.


 


The main differentiating feature between lipomyelocele and lipomyelomeningocele is the position of the placode–lipoma interface. With a lipomyelocele, the placode–lipoma interface lies within the spinal canal. With a lipomyelomeningocele, the placode–lipoma interface lies outside of the spinal canal due to expansion of the sub-arachnoid space. In both cases, syringomyelia is a commonly associated finding. Lipomyelocele and lipomyelomeningocele account for 20–56% of occult spinal dysraphism and 20% of skin-covered lumbosacral masses.


 


 


 


 


References:


Acta Neurochir (Wien). 2009 Mar;151(3):179-188


AJR 2010;194:S26–S37


To submit your answer, login first (for Korean radiologists) or send e-mail to balgundol@gmail.com (for non-Korean radiologists)

Correct Answer
Total applicants 37 Correct answers 14
Name Institution
김기욱 국군대전병원, 전문의
김창현 전문의
최형인 국군의무학교, 전문의
전인환 전문의
이준영 전공의
여현정 전공의
이혜란 전문의
강지희 서울대학교병원, 전공의
고에스더 전문의
권소이 전문의
이은채 전문의
손상욱 군의관, 전문의
김보람 전문의
유해원 전공의


Comment