Dermoid cyst in the posterior fossa accompanied by Klippel-Feil syndrome

Objects: Dermoid cysts accompanied by Klippel-Feil syndrome are uncommon, a nd the coincidence of these two rare diseases suggests an interesting idea about the pathogenesis of a dermoid cyst, which the authors consider with r eference to an actual case. A posterior fossa dermoid cyst with dermal sinu s and Klippel-Feil syndrome are reported in the same patient. A 23-year-old woman was admitted to hospital with progressive headaches. Methods: Cervical radiography demonstrated C4-5 vertebral fusion, and magne tic resonance imaging revealed a large cystic mass in the midline of the po sterior fossa. The cystic lesion was totally removed along with the accompa nying dermal sinus. It was histopathologically diagnosed as a dermoid cyst. Conclusion: The rare coincidence of a dermoid cyst and Klippel-Feil syndrom e suggests the possibility that a disturbance in the mesoderm before the fo urth week of gestation might play an important part in the causation of der moid cyst.