Acute large-vessel occlusion due to an infected thrombus formation induced by invasive sphenoid sinus aspergillosis: illustrative case.

backgroundThe authors describe a rare case of acute large-vessel occlusion due to an infected thrombus formation that was induced by invasive sphenoid sinus aspergillosis. OBSERVATIONS: An 82-year-old man with a history of immunoglobulin G4-related disease and long-term use of steroids and immunosuppressants was admitted to the authors' hospital with severe right hemiparesis. Cerebral angiography revealed occlusion of the left internal carotid artery (ICA). He underwent thrombectomy, resulting in successful recanalization. However, severe stenosis was evident in the left ICA cavernous segment. Pathological analysis of the retrieved thrombus identified Aspergillus. Postoperative magnetic resonance imaging revealed sinusitis in the left sphenoid sinus as a possible source of the infection. The patient's general condition deteriorated during the course of hospitalization due to refractory aspiration pneumonia, and he died 46 days after thrombectomy. Pathological autopsy and histopathological investigation of the left ICA and the left sphenoid sinus showed that Aspergillus had invaded the wall of the left ICA from the adjacent sphenoid sinus. These findings indicate a diagnosis of acute large-vessel occlusion due to infected thrombus formation induced by invasive sphenoid sinus aspergillosis. LESSONS: Pathological analysis of a retrieved thrombus appears useful for identifying rare stroke etiologies such as fungal infection.