Syringomyelia is a not infrequent pathology that develops related to changes in cerebrospinal fluid dynamics due to many etiological factors. The development of syringomyelia through a spinal arachnoid cyst is quite rare and has been defined in only 31 cases in the literature. A case due to thoracic epidural lipomatosis has also been reported. There have been no previous reports of thoracic region epidural lipomatosis with underlying arachnoid cyst and syringomyelia as in our case. We present a 27-year-old patient who developed thoracic arachnoid cyst and underlying syringomyelia because of the pressure of the thoracic epidural fat tissue and also evaluate the characteristics of patients with syringomyelia by virtue of an arachnoid cyst previously reported in the literature.