Intraventricular giant cavernous malformation mimicking central neurocytoma characterized by digital subtraction angiography: illustrative case.

BACKGROUND: Cavernous malformations (CMs) are low-flow vascular lesions that are typically angiographically occult due to slow blood transit through dysplastic vascular channels. Diagnosis is established using MRI, which characteristically demonstrates a heterogeneous popcorn-like lesion with a hemosiderin rim. Rare reports, however, have described subtle angiographic abnormalities. Intraventricular CMs are particularly uncommon, and their angiographic features remain poorly characterized. OBSERVATIONS: The authors report the case of a 30-year-old man presenting with seizures and a large heterogeneous intraventricular mass initially interpreted as a central neurocytoma. Digital subtraction angiography demonstrated lenticulostriate arterial feeders forming a fine vascular meshwork with punctate venous stasis. The patient underwent left frontal craniotomy for gross-total resection under neuronavigation, and intraoperative and histopathological findings confirmed a CM. A focused literature review identified prior reports of angiographically detectable CMs demonstrating tumor stain, venous pooling, or capillary blush. LESSONS: Although CMs are classically angiographically occult, subtle angiographic findings may occasionally be detected, particularly in large or atypically located lesions. Recognition of these findings may aid differentiation from other vascular or intraventricular neoplastic lesions and assist preoperative planning. This case expands the limited literature on angiographically detectable intraventricular CMs and highlights a complementary role for angiography in selected cases. https://thejns.org/doi/10.3171/CASE26530.