Chordoid glioma: report of two rare examples with unusual features.

Background. Chordoid glioma, a rare tumour of the third ventricle, represents a distinct clinico-pathologic entity. Thirty nine examples have been described in the literature, mostly in females and in the third ventricle. The clinical presentation is variable but they tend to occur mostly in adults. There is only one report of a chordoid glioma in a 12 year old child. Finding. This paper describes two examples of chordoid glioma in a seven year old female child and a 70 year old male respectively. Radiologically, the paediatric chordoid glioma was located in the juxtaventricular region in the occipital horn of the lateral ventricle and was of mixed density whereas the adult patient had a typical third ventricle location with homogenous contrast enhancement. Gross total surgical removal was achieved in both but the adult patient died post-operatively due to intra ventricular bleeding and bacterial meningitis. The younger patient is doing well at the last follow up two years post-operatively. Microscopically, both showed the classic morphology of chordoid glioma. Ultrastructural examination was suggestive of ependymal differentiation. Conclusion. The younger age and unusual location are some of the rare features which need documentation and have not been described earlier. We propose that chordoid glioma is a variant of an ependymoma (WHO grade II) which arises from tanycytes and should be included in the WHO classification of brain tumors. [ABSTRACT FROM AUTHOR]