Clinico-pathological features and molecular background of oligodendrogliomas

Background: Diffuse gliomas are the most frequent primary central nervous system (CNS) neoplasms, originating from the parenchyma itself, oligodendrogliomas accounting for approximately 10% of cerebral gliomas. For the past 20 years, the study of genetic/molecular mechanisms of glioma genesis and progression has gradually come into focus. However, the biological and clinical significance of these mutations are still to be completely characterized. The purpose of this article is to describe our clinical experience with oligodendrogliomas and to review the current literature, in order to better describe the characteristics of the molecular/genetic oligodendroglioma subgroups. Methods: We performed a single-institution retrospective study that included 66 patients with oligodendrogliomas operated in our department between January 2011 and December 2018. Results: Our study included 26 female patients (39%) and 40 male patients (59%). The mean age at presentation was 39.9year-old (range 26-59year-old). The tumours were located predominantly in the right hemisphere (53%), the majority being situated in the frontal lobe (59%). 64% of the patients had signs of mass effect on the imaging studies, 13% presented with brain herniation syndromes, and 16 % of the surgically treated patients had a relapse with regrowth and malignant transformation of the tumour. The most common complaint that the patients had at admission was a headache. Seizures were the second most common symptom that determined the patients to seek medical attention. Conclusion: The expanding knowledge regarding the genetic alterations of oligodendroglial tumours could lead to significant changes in treatment strategies. However, the utility of each particular marker in planning the treatment has yet to be established. Emerging data will, most likely, improve outcome prediction and adjuvant therapy strategies by identifying the patients most likely to benefit from a particular treatment.