Abstract
Introduction
Retained medullary cord (RMC) is thought to be a product of arrested secondary neurulation during the regression phase. A cord-like structure with a caudal non-functional part ends at the cul-de-sac. If the arrest occurs at the cavitation phase of secondary neurulation, the medullary cord has a cystic portion making “RMC of cystic type.”
Clinical presentation
We report a case of a 4-month-old girl who had a low-lying conus with an extradural-looking dorsal cyst. Preoperative diagnosis was RMC with a lumbosacral extradural cyst such as an arachnoid cyst. At surgery, we found that the extradural cyst was an extension of dural sac with the caudal portion of the cystic RMC inside. The RMC was untethered and the dural sac was reconstructed. The histopathologic examination revealed findings compatible with cystic RMC attached to the cul-de-sac.
Conclusions
We regard this case as an intermediate form between the typical RMC in which is regarded as regression arrest occurred after the terminal balloon collapsed and the medullary cord detached from the skin to the normal cul-de-sac, and the terminal myelocystocele which is considered the result of arrest at the phase of the persisted terminal balloon attached to the skin.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Pang D, Zovickian J, Moes GS (2011) Retained medullary cord in humans: late arrest of secondary neurulation. Neurosurgery 68:1500–1519 discussion 1519
Kim KH, Lee JY, Wang KC (2020) Secondary neurulation defects-1 : retained medullary cord. J Korean Neurosurg Soc 63:314–320
Pencovich N, Ben-Sira L, Constantini S (2013) Massive cystic dilatation within a tethered filum terminale causing cauda equina compression and mimicking syringomyelia in a young adult patient. Childs Nerv Syst 29:141–144
Sade B, Beni-Adani L, Ben-Sira L, Constantini S (2003) Progression of terminal syrinx in occult spina bifida after untethering. Childs Nerv Syst 19:106–108
Yang H-J, Lee D-H, Lee Y-J, Chi JG, Lee JY, Phi JH, Kim S-K, Cho B-K, Wang K-C (2014) Secondary neurulation of human embryos: morphological changes and the expression of neuronal antigens. Childs Nerv Syst 30:73–82
Lee JY, Kim SP, Kim SW, Park S-H, Choi JW, Phi JH, Kim S-K, Pang D, Wang K-C (2013) Pathoembryogenesis of terminal myelocystocele: terminal balloon in secondary neurulation of the chick embryo. Childs Nerv Syst 29:1683–1688
Yang H-J, Wang K-C, Chi JG, Lee M-S, Lee Y-J, Kim S-K, Cho B-K (2003) Neural differentiation of caudal cell mass (secondary neurulation) in chick embryos: Hamburger and Hamilton stages 16–45. Brain Res Dev Brain Res 142:31–36
Pang D, Zovickian J, Lee JY, Moes GS, Wang K-C (2012) Terminal myelocystocele: surgical observations and theory of embryogenesis. Neurosurgery 70:1383–1405
Murakami N, Morioka T, Shimogawa T, Hashiguchi K, Mukae N, Uchihashi K, Suzuki SO, Iihara K (2018) Retained medullary cord extending to a sacral subcutaneous meningocele. Childs Nerv Syst 34:527–533
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
There are no conflicts of interest for all authors.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Kim, K.H., Lee, J.Y., Yang, J. et al. Cystic retained medullary cord in an intraspinal J-shaped cul-de-sac: a lesion in the spectrum of regression failure during secondary neurulation. Childs Nerv Syst 37, 2051–2056 (2021). https://doi.org/10.1007/s00381-020-04943-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00381-020-04943-6