Severe amnestic-cognitive syndrome after right-sided resection in a patient with bilateral trigonal choroid plexus xanthogranulomas: illustrative case.

Choroid plexus xanthogranulomas are rare, typically incidental intraventricular lesions that infrequently become symptomatic. When symptomatic, they most often present with headache or hydrocephalus, whereas cognitive sequelae and postoperative neuropsychological outcomes remain poorly characterized. A 63-year-old right-handed man with bilateral trigonal intraventricular lesions, larger on the right, presented with headaches and a history of subjective progressive memory complaints. He underwent resection of the right-sided lesion through a right temporoparietal approach. Immediately after surgery, he developed a severe and persistent amnestic-cognitive syndrome with profound inability to retain new information, confabulation, reduced insight, and marked remote-memory disturbance. Neuropsychological evaluation 3 months postoperatively demonstrated severe anterograde impairment in verbal learning and delayed visuospatial recall, together with substantial retrograde memory impairment involving autobiographical episodic recollection, personal semantic memory, and public semantic knowledge. This case suggests that bilateral trigonal xanthogranulomas and their surgical treatment may place distributed memory networks at substantial risk. Because formal preoperative neuropsychological testing and direct review of the original preoperative MRI were unavailable, the relative contributions of preexisting bilateral disease burden and postoperative network disruption cannot be fully separated. The case supports broader baseline cognitive assessment, precise laterality-specific surgical description, and structured postoperative neuropsychological follow-up for lesions near posterior medial and limbic white-matter pathways.