BACKGROUND Dermoid cysts in the myelomeningocele (MMC) site are thought to arise in a delayed fashion because of iatrogenic implantation of dermoid elements at the time of the initial repair surgery. However, there have been few reports on dermoid elements already present at birth. CLINICAL PRESENTATION We report a patient, in whom dermoid cyst was located at dorsal aspect of the conus medullaris in the MMC sac. Between 23+3 and 24+4 weeks of gestation, rupture of the MMC sac occurred. At this time of gestation, we speculate that rupture of the dermoid cyst also occurred and dissemination of the cyst contents caused chemical arachnoiditis in the MMC sac. At the age of 1 day, surgery to repair MMC and postoperative histological findings revealed these rare pathologies. CONCLUSION Physicians should be aware of the possibility of rupture of a dermoid cyst in the MMC sac during fetal period.

中文翻译：

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在最初的修复手术中发现了脊髓膜囊膨出囊中的延髓圆锥状皮样囊肿。

背景技术由于在最初的修复手术时皮肤源性皮肤元素的医源性植入，因此认为髓脑膜囊肿（MMC）部位的皮肤样囊肿以延迟的方式出现。但是，关于出生时已存在的皮肤样元素的报道很少。临床表现我们报告了一名患者，其中皮肤样囊肿位于MMC囊中延髓的背面。在妊娠的23 + 3至24 + 4周之间，MMC囊破裂。在妊娠时，我们推测皮样囊肿也发生破裂，囊肿内容物的扩散引起MMC囊中的化学蛛网膜炎。在1日龄时，修复MMC的手术和术后组织学发现揭示了这些罕见的病理。