Chordoid glioma: a subtype of brain tumour still poorly understood

Chordoid gliomas are rare brain tumours, resulting from the excessive and cancerous proliferation of specific cells composing the neuronal microenvironment.

It develops exclusively in the third anterior ventricle, the brain cavity close to the base of the skull (circled part on the MRI on the right).

It is most often manifested in middle-aged women (30-60) by memory loss and headaches. It is non-invasive (no metastasis) but has a poor prognosis because of its location and surgical morbidity.

The pathological, histological and molecular characteristics of this tumour are still relatively unknown since only about 85 cases have been reported since its description in 1998 (Brat et al).  The low number of cases and the rarity of samples, due to the difficulty of surgical removal of the tumours, are the main obstacles to further study of this type of glioma.

The teams of Professor Marc Sanson and Dr Emmanuelle Huillard have succeeded in collecting 16 cases of chordoid gliomas and using current sequencing techniques, they have deciphered the genome of these tumours and highlighted a mutation of a gene present in all the samples. The altered protein present in the samples is well known since it is altered in many cancers. However, this mutation has never yet been observed in other types of cancers, making it a possible signature of chordoid gliomas.

A detailed investigation of the molecular consequences of this “founder” mutation is underway in order to identify the mechanisms of development of these tumors and to establish new therapeutic perspectives for this rare subtype of glioma.

A recurrent point mutation in PRKCA is a hallmark of Chordoid Gliomas.
Rosenberg S, Simeonova I, Bielle F, Verreault M, Bance B, Le Roux I, Daniau M, Nadaradjane A, Gleize V, Paris S, Marie Y, Giry M, Polivka M, Figarella-Branger D, Aubriot-Lorton MH, Villa C, Vasiljevic A, Lechapt-Zalcman E, Kalamarides M, Sharif A, Mokhtari KM, Pagnotta SM, Iavarone A, Lasorella A, Huillard E, Sanson M.
Nature Communications, 2018, sous presse.