One of the key issues of tumour brain surgeries is to clearly define the borders of the tumor. The investigators proposed to evaluate the feasibility of intraoperative fluorescein guidance. Patients will be identified from the list of patients operated on under fluorescence to collect clinical datas. Surgical videos will be analyzed to assess the presence of intraoperative fluorescence and its subjectively judged intensity. MRI data will be extracted from the radiological reports to assess quality extraction. No additional data will be produced

Gangliogliomas typically present as a slow-growing, cystic mass taking contrast, while dysembryoplastic neuro-epithelial tumors commonly show microcystic patterns, inconstant contrast-enhancement and are preferentially located on the internal face of the temporal lobe. The cornerstone of the treatment of these two entities remains surgery, as it provides good oncological outcomes and control of seizures. Surgical resection keeps a major role for these tumors. Thus, one of the key issues is to clearly define the borders of the tumor during surgery, a point of considerable importance for these curable lesions. Then, the investigators proposed to evaluate the feasibility of intraoperative fluorescein guidance, a technique based on the staining of blood-brain barrier breakdown areas with fluorescein. Patients will be identified from the list of patients operated on under fluorescence maintained by the department since the acquisition of the technique. Clinical datas will be collected and surgical videos will be analyzed to assess the presence of intraoperative fluorescence and its subjectively judged intensity (absent, weak, medium, strong). MRI data (quality of excision: total, subtotal or partial according to usual criteria) will be extracted from the radiological reports. No additional data will be produced

Inclusion Criteria:

• Over 18 years old patient
• Fluoroguided removal of a histologically proven Ganglioglioma or Dysembryoplastic Neuroepithelial Tumors between 2015-2018
• Surgical video available

Exclusion Criteria:

• Absence of surgical video
• Adults who are subject to legal protection (protection of justice, guardianship, guardianship)
• Patient objecting to the use of their data

Seven patients (5 men, 2 women, mean age 30 year-old) underwent fluorescein-guided resection of gangliogliomas (5/7; 4 WHO Grade I, 1 WHO Grade III) and DNT (2/7).