====== Dermoid cyst associated with colloid cyst ======

[[Intracranial dermoid cyst]] and [[colloid cyst]]s of the [[third ventricle]] are rare benign [[congenital]] lesions of early [[adult]]hood. Both [[lesion]]s are thought to be [[congenital]] in origin however association is rare. 

Cheng et al. from the Department of Neurosurgery, [[Stanford]] University School of Medicine in [[1999]] reported a case of nasal [[dermoid sinus]] cyst associated with [[colloid cyst]] of third ventricle and proposed a fascinating theory of “[[anterior neuropore]] corridor defects” to explain the spectrum of these associated rare midline lesions. According to this theory, defective closure of [[situs neuroporicus]] promotes the [[neuroepithelium]] adjacent to [[commissural plate]] derivatives to form a vacuolated paraphysis growing slowly as colloid cyst of the third ventricle

The reported case was a 16-year-old male with both a nasal dermoid sinus cyst (NDSC) and a third ventricle colloid cyst. The NDSC was excised via a single-stage combined intracranial-extracranial approach and the third ventricle colloid cyst was resected endoscopically
((Cheng ML, Chang SD, Pang D, Adler JR. Intracranial nasal dermoid sinus cyst
associated with colloid cyst of the third ventricle. Case report and new
concepts. Pediatr Neurosurg. 1999 Oct;31(4):201-6. PubMed PMID: 10705930.
)).

Similar derivation from paraphysial remnants was also reported by Nagaraju et al.
((Nagaraju S, O'Donovan DG, Cross J, Fernandes H. Colloid cyst of the third
cerebral ventricle with an embryological remnant consistent with paraphysis
cerebri in an adult human. Clin Neuropathol. 2010 May-Jun;29(3):121-6. PubMed
PMID: 20423684.
))
, in 2010 supporting Cheng's hypothesis
((Kurwale N, Kumar R, Sharma MC, Sharma BS. Suprasellar dermoid cyst associated 
with colloid cyst of the third ventricle: Disordered embryogenesis or a mere
coincidence? J Neurosci Rural Pract. 2013 Jul;4(3):345-7. doi:
10.4103/0976-3147.118803. PubMed PMID: 24250183; PubMed Central PMCID:
PMC3821436.
)).


Kurwale et al. report a 22-year-old male with suprasellar dermoid cyst and colloid cyst of the third ventricle presenting simultaneously
((Kurwale N, Kumar R, Sharma MC, Sharma BS. Suprasellar dermoid cyst associated 
with colloid cyst of the third ventricle: Disordered embryogenesis or a mere
coincidence? J Neurosci Rural Pract. 2013 Jul;4(3):345-7. doi:
10.4103/0976-3147.118803. PubMed PMID: 24250183; PubMed Central PMCID:
PMC3821436.
)).

===== References =====