Surgical Treatment of Congenital Dermal Sinus: An Experience of 56 Cases

<b><i>Objective:</i></b> This study aims to assess the impact of early diagnosis and surgery on children with congenital dermal sinus, investigate the relationship between MRI findings and extent of surgical exploration, and summarize our clinical experience with the surgical management in cases with central nervous system (CNS) infection. <b><i>Methods:</i></b> The skin features, preoperative MRI images, intraoperative findings, postoperative pathological characteristics, and prognoses of 56 children with congenital dermal sinus were analyzed retrospectively. <b><i>Results:</i></b> All the children had a pinpoint ostium in the skin, and 52 out of the 56 children (92.9%) had intraspinal dermoid cysts or epidermoid cysts. Before surgery, MRI did not show intraspinal lesions in 13 children, and surgery revealed intradural lesions in 9 of these children (69.2%). Among 46 children without CNS infection, 16 children had neurological impairment before surgery. After surgery, recovery was complete in 36 children, partial in 9 children, and absent in 3 children. All children with CNS infection had neurological impairment before surgery. After surgery, the condition improved in 8 children and exacerbated in 2 children. Children without CNS infection had statistically significantly better prognosis than children with CNS infection (<i>p</i> = 0.03). <b><i>Conclusion:</i></b> A pinpoint ostium in the dorsal midline is the characteristic feature of congenital dermal sinus. In cases without intraspinal lesions on MRI, the spinal canal should be explored intraoperatively to ensure complete removal of the lesion and prevent recurrences. In cases without CNS infection, early diagnosis and timely surgery are beneficial to the recovery of nerve function.

Congenital Dermal Sinus Elements in Each Tethering Stalk of Coexisting Thoracic Limited Dorsal Myeloschisis and Retained Medullary Cord

<b><i>Introduction:</i></b> The embryogenesis of limited dorsal myeloschisis (LDM) likely involves impaired disjunction between the cutaneous and neural ectoderms during primary neurulation. Because LDM and congenital dermal sinus (CDS) have a shared origin in this regard, CDS elements can be found in the LDM stalk. Retained medullary cord (RMC) is a closed spinal dysraphism involving a robust, elongated, cord-like structure extending from the conus medullaris to the dural cul-de-sac. Because the RMC is assumed to be caused by impaired secondary neurulation, concurrent RMC and CDS cannot be explained embryologically. In the present article, we report a case in which CDS elements were noted in each tethering stalk of a coexisting LDM and RMC. <b><i>Case Presentation:</i></b> A 2.5-month-old boy with left clubfoot and frequent urinary and fecal leakage had 2 tethering tracts. The upper tract, which ran from the thoracic tail-like cutaneous appendage, had CDS elements in the extradural stalk and a tiny dermoid cyst in the intradural stalk immediately after the dural entry. In the lower tract, which ran from the lumbosacral dimple, the CDS as an extradural stalk continued to the RMC at the dural cul-de-sac. Both stalks were entirely resected through skip laminotomy/laminectomy at 1 stage to untether the cord and resect the CDS elements. <b><i>Conclusion:</i></b> Surgeons should be aware that CDS elements, in addition to LDM, may coexist with RMC that extends out to the extradural space.