RESUMEN
Congenital dermal sinus (CDS) is a rare entity widely known to occur as a result of the of the failure of the neuroectoderm to separate from the cutaneous ectoderm during the process of neurulation at the third to fifth week of gestation. The lesion can occur at any level of the craniospinal axis, but are located predominantly at the lumbosacral and occipital region. CDS of thoracic region and cervical region are rare. The patient with CDS presents with meningitis and/or mass effect from the associated inclusion tumor. They are usually dermoid or epidermoid cyst. Teratoma is rarely associated with CDS. We report our experience of CDS an 11-month old boy associated with an intramedullary dermoid tumor at the thoracic region, and together we report a review of the literature.