Introduction: The optimal management of WHO grade II gliomas (GIIG) is currently one of the most controversial issues in neuro-oncology.
Aim: This paper discusses the most controversial aspects of management of these tumors, based on a review of the literature of the last 20 years.
Development: Patients with GIIG often suffer cognitive and emotional disorders that go unnoticed in daily clinic, which significantly affect the quality of life. These tumors do not remain stable, as they grow slowly and steadily. In fact, growth rate is a reliable marker of their biological behaviour, with rapid growth being a marker of malignancy. Current neuro-imaging studies and stereotactic biopsy are not reliable enough for diagnosis of GIIG, thus many authors consider that a definitive diagnosis can only be obtained with a detailed histological examination after extensive surgical resection. An increasing number of studies support the prognostic impact of surgery, as it delays malignant transformation and increases survival. GIIG are frequently located in eloquent brain areas; intraoperative electrical stimulation mapping is now considered the gold standard to remove these tumors with a low risk of sequelae.
Conclusions: There is growing scientific evidence against a 'wait-and-see' management of GIIG. Surgery is considered nowadays by most authors as the first step in the diagnosis and treatment of these tumors.