Coexistence of histologically distinct intracranial tumors: Case series, literature review, and meta-analysis

Background: Multiple intracranial tumors of different histological origin occurring in the same patient are uncommon. The annual incidence is estimated at <1/million, and the management options remain demanding in some cases due to different pathogenesis and biological behaviors. Methods: We retrospectively reviewed six patients operated on at our department between 2011 and 2025 who presented with two concurrent non-adjacent brain tumors of distinct pathology, one meningioma and one intraparenchymal lesion. This is followed by a narrative literature review conducted according to preferred reporting items for systematic reviews and meta-analyses guidelines and a meta-analysis along with exploratory meta-regression analyses. Results: Our series had a mean age of 56 years, with the female sex twice as common; the most common tumor combination was a meningioma with a glioma. The literature review included 76 studies, with 16 of them getting meta-analyzed. There was no sex predilection, and the pooled mean age was 52 years. Meningioma along with a glioma is the most common tumor combination, and the most encountered tumor types are a meningioma and a pituitary adenoma. Mortality rates were low ( P < 0.001), and one-stage surgery was the main applied treatment; a positive trend between one-stage surgery performance and elder populations was noticed ( P = 0.052). Conclusion: The presence of such brain neoplasms in one patient is a compelling medical entity, and its pathogenesis remains questionable. Surgical treatment, at one or two stages, remains the gold standard, while further research needs to be conducted in order to explain any possible pathogenesis and reinforce management options.