Klippel-Feil syndrome in association with posterior fossa suboccipital dermoid cyst

Abstract

We present the second case of Klippel-Feil syndrome in association with a posterior fossa dermoid cyst extending through the occipital bone and presenting as a suboccipital subcutaneous mass. We describe its radiographic, CT, and MRI appearances as well as on MRI diffusion-weighted images. Posterior cranial fossa dermoid cysts and sinuses should be added to the list of congenital abnormalities which must be sought in patients with Klippel-Feil syndrome. Diffusion-weighted images of brain may differentiate these masses from cerebral spinal fluid collections.

Intracranial dermoid cysts: variations of radiological and clinical features

“…Aksoy et al reported a hyperintense DWI signal in a posterior fossa dermoid that pre-operatively mimicked an epidermoid. The solid components of the dermoid led to decreased diffusion within the tumour compared to purely cystic lesions [3]. Other authors also reported a few examples in which the CT appearance was hyperdense, and even partial rim enhancement has been documented [8,9,13,21,22,27,33].…”

“…It was recommended to use fluid attenuated inversion recovery (FLAIR) sequences and DWI to distinguish epidermoids from cystic lesions, but as demonstrated by our patient 4, histopathologically confirmed dermoids can resemble epidermoids due to their bright signal on DWI [7,10]. Only few studies on the DWI appearance of intracranial dermoids exist [3,35]. Aksoy et al reported a hyperintense DWI signal in a posterior fossa dermoid that pre-operatively mimicked an epidermoid.…”

Posterior Fossa Dermoid Cysts in Association with Klippel-Feil Syndrome: Report of Three Cases

“…However, a case of squamous cell carcinoma dedifferentiation has been reported, and a few cases of rupture of the cyst leading to aseptic meningitis have been described. 3,7 Several hypotheses have been proposed to explain the embryologic association of a posterior fossa dermoid and KFS. Failure of segmentation of the cervical sclerotomes leads to the Klippel-Feil anomaly and occurs after the formation of the entire neuraxis.…”

“…6 Diffusionweighted MR imaging is useful to differentiate epidermoid tumors from arachnoid cysts and CSF collections, which are otherwise indistinguishable. 7 Specifically, epidermoid tumors show marked increased signal intensity on diffusion-weighted images, whereas arachnoid cysts and CSF collections are generally hypointense following signal intensity of CSF. 10 Dermoid cysts should be suspected when recurrent meningitis, mirror movements, or a midline posterior fossa mass at the craniocervical junction, especially with an associated occipital soft tissue mass, with or without drainage are found in patients with KFS.…”

Cerebellar Dermoid Cyst with Occipital Dermal Sinus

“…These tumors may be associated with dysraphic disorders [9]. In this way, the dermoid cyst could be associated with dermal sinus, myelomeningocele and even Klippel-Feil syndrome [6, 10]. Dermoid cysts contain appendages of skin, such as hair follicles, sweat and sebaceous glands.…”