The role of neurosurgeon in the multidisciplinary approach to ectopic or bifocal intracranial germinoma: A systematic review and report of two illustrative cases

Background: Pure germinoma typically originates from the midline and is usually found in the pineal and suprasellar regions in 76–90 % of cases. When it is in both regions, it is considered bifocal (10 % at diagnosis). If pure germinoma is located outside of the midline, it is considered ectopic, with a global incidence of about 0.7 %. The study aims to describe the clinical and surgical approach to patients with atypical intracranial ectopic germinoma (IEG) and bifocal germinoma (BG) through a literature review with the goal to delineate the correct diagnostic and therapeutic pathway, to reduce the diagnostic delay and improve the prognosis of these patients. Methods: A systematic review of the literature in most common electronic database (PubMed, Ovid MEDLINE and Ovid EMBASE) on IEG and BG, in according with the “PRISMA statement” criteria, from January 1990 to September 2022 was done. In addition, two rare cases of IEG and BG were reported. Results: This systematic review included 16 papers (20 patients) with a final diagnosis of IEG and 30 papers (121 patients) with a final diagnosis of BG. IEGs seems to involve primary basal ganglia (40 %) and corpus callosum (40 %). For IEGs, biopsy (70 %, 14 cases out of 20) was the most common surgical approach: open approach (35 %), stereotactic minimally invasive approach (30 %) or endoscopic trans-sphenoidal approach (5 %). Partial resection was performed in 10 % of cases, whereas a total resection was performed in 20 % of cases. Also for BGs, biopsy was the most common surgical approach in 80 % of patients, whereas surgical resection (partial or total) was performed in 5.3 % of patients. Conclusion: IEG and BG are rare type of primary intracranial germ cell tumor, whose unusual location often can cause delays in diagnosis, which can have a significant impact on the patient's prognosis and requiring a multidisciplinary and timely approach. © 2024 Elsevier B.V.