Terminal myelocystocele (TMC) and dermal sinus tract (DST) are uncommon forms of skin-covered spinal dysraphism, each arising from distinct embryological mechanisms. The objective of this report is to present, for the first time in the literature to our knowledge, the clinical features, diagnostic evaluation, surgical management, and detailed imaging description of this uncommon association. We present the case of a female neonate with concomitant TMC and DST. Magnetic resonance imaging demonstrated a trumpet-shaped TMC associated with sacral osseous dysraphism and a DST extending from C7-T1 to the skin surface. Both malformations were surgically treated in a single session. The malformed distal neural tissue of the TMC was resected, and the DST was excised completely. Postoperatively, the patient developed a transient lumbar cerebrospinal fluid leak, which resolved with conservative management, and she remained neurologically intact at discharge. Histopathology confirmed malformed neural proliferation in the TMC and squamous-lined tract tissue in the DST. From an embryological perspective, the dual occurrence of TMC and DST highlights that neural tube formation can be disrupted at different stages of development in the same individual. Timely diagnosis and surgical management are critical to prevent complications. Addressing both anomalies in a single operative setting proved feasible and yielded a favorable short-term outcome. Further studies are needed to elucidate the intricate mechanisms involved.

Lumbar (non-terminal) myelocystocele is a rare form of closed spinal dysraphism which is characterized by posterior bony defect [1-3], a herniated segment of the spinal cord associated with cystic dilatation of the central canal [1-3], and surrounded by cyst filled with CSF in the subarachnoid space i.e. cyst-within-a-cyst. [1-4] The mass is covered by intact skin and variable amounts of subcutaneous fat which is often attached to neural tissue. [1-3] Surgery is advocated to untether the cord and reconstruct the neural tube which will prevent further neurological deterioration. [1-3] In this video, we present the case of a 7-month-old boy who was presented with skin skin-covered lumbar mass after birth. He had left foot drop with no movement in the toes and right foot inversion with associated weakness in the toes. There were no developmental delays and he did not have anorectal anomalies. Magnetic Resonance Imaging (MRI) spine confirmed the diagnosis of lumbar myelocystocele, and urinary flow studies showed good bladder capacity with reasonable voids. The patient underwent spinal cord untethering, neurulation of the neural placode, and duraplasty with an artificial dural graft to increase the cord-sac ratio. [5-7] Postoperative motor power was similar to baseline. The urinary catheter was removed three weeks after surgery with adequate voiding. The were no concerns related to the wound. The parents consented to the procedure and the publication of the patient's video. Institutional Review Board approval was not required.

Terminal myelocystocele (TMC) is rare form of closed neural tube defect (NTD), accounting for approximately 4-8% of occult spinal dysraphisms. It is defined by cystic dilatation of the distal central canal herniating through a posterior spina bifida, typically covered by intact skin. Frequently associated with multisystem malformations, its pathogenesis remains debated, with theories involving disordered secondary neurulation, abnormal cerebrospinal fluid (CSF) dynamics, and failed disjunction between ectodermal layers. We present the case of a male neonate with a lumbosacral mass identified at birth. Magnetic resonance imaging (MRI) revealed a 50 mm TMC associated with a separate meningocele, syringomyelia, scoliosis, butterfly vertebra, and Chiari II malformation. Surgical correction at 2 weeks of age included detethering of the spinal cord, partial cyst wall resection, and dural patch closure under intraoperative neurophysiological monitoring. The postoperative course was uneventful, and at 3-month follow-up the patient remained neurologically stable with normal developmental milestones. This case underscores the clinical and radiological hallmarks of TMC, as well as the importance of early surgical intervention to prevent progressive neurological deterioration. MRI remains the diagnostic gold standard and guides surgical planning. We introduce a novel hypothesis drawing parallels with Chiari malformations, suggesting that fibrous bands and altered CSF hydrodynamics may contribute to cyst enlargement and clinical decline. A multidisciplinary approach and improved understanding of these mechanisms are crucial to optimize outcomes and refine management strategies.

Spinal dysraphism is characterized by failure of fusion at dorsal midline structures through the embryonic developmental stages. A terminal myelocystocele consists of a skin-covered lumbosacral spina bifida and meningocele that directly continuous with the spinal subarachnoid space. A 43-year-old woman who was diagnosed at birth with myelocystocele in the lower segments of the lumbar spine. She was not operated in the early stages of life. At the 43th years of her old, during 9-months, the sac began to progressively increase in size. In our initial examination before surgery, an extremely large skin-covered myelocystocele sac was observed in the thoracolumbar with a diameter of approximately 60 * 70 * 40 cm. patient operated and sac repaired. More than 20 liter of cerebrospinal fluid drainaged from cyst during surgery. The mechanism of cyst enlargement is not well understood. Progressive and severe increase in size of unrepaired myelocystocele sac is possible in old ages even without cerebral hydrocephalus.

Omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex is a rare, life-threatening congenital malformation primarily treated with abdominogenital repair. The optimal indication and timing of neurosurgical interventions for the associated spinal cord lesions remains insufficiently studied. We reviewed spinal dysraphism in OEIS to evaluate the best timing for neurosurgical intervention. We retrospectively reviewed 10 patients with OEIS, analyzing their clinical and imaging data, as well as surgical and pathological findings. Terminal myelocystocele (TMCC) and spinal lipomas were observed in 5 patients each. Of the spinal lipomas, one had a single filar lipoma, while four had double lipomas (3 caudal and dorsal; 1 filar and dorsal). TMCC manifested with severe lower limb motor dysfunction in addition to abdominogenital disorder at birth, with the cyst-induced lumbosacral mass increasing over time. Spinal lipomas were less symptomatic except for abdominogenital issues and demonstrated minimal growth of the intraspinal lipoma over time. Untethering surgery was performed in 8 patients (5 TMCC; 3 spinal lipomas) at a median age of 3 (range, 2-10) months for TMCC and 6 (range, 2-14) months for spinal lipomas. One TMCC patient (surgery at 10 months) experienced postoperative cerebrospinal fluid leakage, necessitating three reoperations. Magnetic resonance imaging is essential to diagnose spinal cord malformations accurately. The necessity and timing of surgical intervention differ between TMCC and spinal lipomas. Since TMCC lesions tend to enlarge, surgery should be performed as soon as the patient's abdominogenital condition stabilizes. For spinal lipomas, surgery should be considered carefully based on the patient's neurological condition.