Coexisting meningioma and intracranial aneurysm: a case for tailored, non-simultaneous management

Background: Olfactory groove meningiomas grow insidiously and often reach large size before detection, as visual decline is readily attributed to more common ocular diseases. Concurrently, the co-occurrence of meningioma and intracranial aneurysm is uncommon, reported in 0.13–1.17% of cases. When the two lesions are adjacent and the aneurysm is favorably configured, current practice favors single-stage resection with aneurysm clipping. However, management becomes less standardized when the aneurysm is anatomically remote, unruptured, and morphologically complex. We present a case in which visual field testing distinguished compressive visual loss from a coexisting cataract and prompted neuroimaging, as well as the individualized management of an incidentally discovered aneurysm.

Case Description: We report the case of a 48-year-old male who presented with several months of progressively worsening blurry vision, with the right side noted to be worse than the left and initially attributed to cataracts. Visual field testing showed a complex pattern of vision loss consistent with predominant bilateral inferior nasal quadrantanopsia. Magnetic Resonance Imaging (MRI) of the brain showed a 51 x 51 x 26 mm enhancing mass at the anterior skull base, with adjacent hyperostosis of the anterior cranial fossa floor and mass effect on the bilateral frontal lobes, radiographically characteristic of meningioma. An unruptured aneurysm superior to the genu of the corpus callosum was also incidentally detected. The patient had no anosmia. Angiography characterized a complex left distal anterior cerebral artery (A2–A3) aneurysm with fusiform dysplastic features and showed tumor vascular supply arising from A1 lenticulostriate perforators, rendering preoperative embolization unsafe. The patient underwent right orbitofrontal craniotomy for subtotal meningioma resection, while the unruptured aneurysm was managed conservatively with surveillance. Pathology confirmed WHO grade 1 meningothelial meningioma. The patient reported visual improvement postoperatively.

Conclusion: This case raises both diagnostic and management considerations. First, a cataract was present, offering a plausible explanation for the patient’s increasingly blurred vision, but could not account for a bilateral visual field defect. Aside from his vision, the examination was unremarkable for anosmia and behavioral and cognitive changes. Visual complaint was therefore the only sign for a 5 cm skull base tumor, where visual field testing redirected the workup toward imaging. Additionally, this case also illustrates an individualized management approach for co-occurring meningioma and aneurysm. When the aneurysm is incidental, unruptured, and anatomically remote or unfavorable for direct treatment, prioritizing the symptomatic lesion while observing the aneurysm is a reasonable, individualized strategy rather than defaulting to simultaneous intervention.