Kurogi Ai, Murakami Nobuya, Morioka Takato, Mukae Nobutaka, Shimogawa Takafumi, Kudo Kyoko, Suzuki Satoshi O, Mizoguchi Masahiro
Department of Neurosurgery, Fukuoka Children's Hospital, Saga, Japan.
Department of Neurosurgery, Harasanshin Hospital, Saga, Japan.
Surg Neurol Int. 2021 Mar 24;12:112. doi: 10.25259/SNI_626_2020. eCollection 2021.
Retained medullary cord (RMC) is a newly defined entity believed to originate from the late arrest of secondary neurulation. Some RMCs contain varying amounts of lipomatous tissues, which need to be differentiated from spinal lipomas, such as filar and caudal lipomas (terminal lipomas).
We surgically treated two patients with a nonfunctional cord-like structure (C-LS) that was continuous from the cord and extended to the dural cul-de-sac, and ran parallel to the terminal lipoma. In both cases, untethering surgery was performed by resecting the C-LS with lipoma as a column, under intraoperative neurophysiological monitoring. Histopathological examination confirmed that the central canal-like ependyma-lined lumen with surrounding neuroglial and fibrocollagenous tissues, which is the central histopathological feature of an RMC, was located on the unilateral side of the resected column, while the fibroadipose tissues of the lipoma were located on the contralateral side.
Our findings support the idea proposed by Pang . that entities such as RMC and terminal lipomas are members of a continuum of regression failure occurring during late secondary neurulation, and the coexistence of RMC and terminal lipoma is not a surprising finding. Therefore, it may be difficult in clinical practice to make a distinct diagnosis between these two entities.
残留脊髓（RMC）是一种新定义的实体，被认为起源于继发性神经管形成的晚期停滞。一些RMC含有不同数量的脂肪组织，这需要与脊髓脂肪瘤相鉴别，如终丝脂肪瘤和尾部脂肪瘤（终末脂肪瘤）。
我们对两名患者进行了手术治疗，他们均有一个无功能的条索状结构（C-LS），该结构与脊髓相连并延伸至硬脊膜盲端，且与终末脂肪瘤平行。在这两例手术中，均在术中神经生理监测下，以脂肪瘤为柱状结构切除C-LS进行松解手术。组织病理学检查证实，具有中央管样、内衬室管膜的管腔以及周围神经胶质和纤维胶原组织，这是RMC的中央组织病理学特征，位于切除柱状结构的单侧，而脂肪瘤的纤维脂肪组织位于对侧。
我们的研究结果支持庞提出的观点，即RMC和终末脂肪瘤等实体是继发性神经管形成晚期发生的一系列退化失败的成员，RMC和终末脂肪瘤的共存并非罕见发现。因此，在临床实践中可能难以对这两种实体进行明确诊断。
