Association of Craniovertebral Junction Anomalies, Klippel-Feil Syndrome, Ruptured Dermoid Cyst and Mirror Movement in One Patient: A Unique Case and Literature Review.

The Klippel-Feil syndrome (KFS) has been reported to be associated with intracranial neoplasms, most frequently epidermoid or dermoid cysts. To our knowledge, however, patients who present with a posterior fossa dermoid cyst (DC) and KFS are extremely rare with only 24 previously reported cases in the English literature worldwide. Therefore, we present the first report of a patient with a craniocervical ruptured DC accompanied by craniovertebral junction (CVJ) anomalies, KFS and mirror movement. Meanwhile, a literature review of KFS accompanying with posterior fossa DC discusses these conditions from the embryological, anatomical, clinical and therapeutic perspectives. Additionally, the combination of CVJ anomalies, KFS and DC may represent a new syndrome that has previously gone unnoticed.