Nobuya Murakami1, Takato Morioka2, Takafumi Shimogawa2,3, Nobutaka Mukae3, Satoshi Inoha4, Takakazu Sasaguri5, Satoshi O Suzuki6, Koji Iihara3. 1. Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan, murakami.n@fcho.jp. 2. Department of Neurosurgery, Fukuoka Children's Hospital, Fukuoka, Japan. 3. Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. 4. Department of Neurosurgery, Japan Community Health Care Organization (JCHO), Kyushu Hospital, Kitakyushu, Japan. 5. Department of Pathology, Japan Community Health Care Organization (JCHO), Kyushu Hospital, Kitakyushu, Japan. 6. Department of Neuropathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Abstract
BACKGROUND: An ependyma-lined canal with surrounding neuroglial tissues can be present in lumbosacral lipomatous malformations; however, the precise embryological significance is still unclear. METHOD: Six out of 50 patients with lipomatous malformations had ependymal structures. We retrospectively analyzed the clinical, neuroradiological, and histological findings of these patients to demonstrate the relationship with the embryological background of the retained medullary cord (RMC), which normally regresses, but was retained here because of late arrest of secondary neurulation. RESULTS: Five (13.9%) of 36 patients with filar and caudal types and 1 of 3 lipomyelomeningoceles had ependymal structures, while none with dorsal and transitional types had these tissues. Histologically, the ependymal structures surrounded by neuroglial tissue and containing various amounts of adipose tissue bear a striking resemblance to the ependymal structures in RMC. CONCLUSION: The 13.9% incidence of association between the ependymal structures and filar and caudal types is thought to be because of second ary neurulation failure with the same embryological background as that of RMC. Dorsal and transitional types, resulting from primary neurulation failure, therefore, did not have ependymal structures.
BACKGROUND: An ependyma-lined canal with surrounding neuroglial tissues can be present in lumbosacral lipomatous malformations; however, the precise embryological significance is still unclear. METHOD: Six out of 50 patients with lipomatous malformations had ependymal structures. We retrospectively analyzed the clinical, neuroradiological, and histological findings of these patients to demonstrate the relationship with the embryological background of the retained medullary cord (RMC), which normally regresses, but was retained here because of late arrest of secondary neurulation. RESULTS: Five (13.9%) of 36 patients with filar and caudal types and 1 of 3 lipomyelomeningoceles had ependymal structures, while none with dorsal and transitional types had these tissues. Histologically, the ependymal structures surrounded by neuroglial tissue and containing various amounts of adipose tissue bear a striking resemblance to the ependymal structures in RMC. CONCLUSION: The 13.9% incidence of association between the ependymal structures and filar and caudal types is thought to be because of second ary neurulation failure with the same embryological background as that of RMC. Dorsal and transitional types, resulting from primary neurulation failure, therefore, did not have ependymal structures.