Clinical characteristics and detection of MYB-QKI fusions in patients with angiocentric glioma.

Purpose: Angiocentric glioma (AG), a benign tumor identified within the last two decades, was officially included in the 2007 WHO Classification of Tumors of the Central Nervous System, WHO grade I. The tumor is relatively rare, with only approximately 100 cases reported. We aim to complement the characteristics and long-term prognosis of AG, as well as to detect MYB-QKI fusions.

Methods: The characteristics of all cases collected between 1 March 2009 and 1 March 2023 at the Beijing Sanbo Brain Hospital, Capital Medical University, were summarized and analyzed. Additionally, all fourteen patients were tested for MYB-QKI fusions.

Results: AG more predominantly occurs in adolescents (median age 16.5-year-old), and commonly presents with drug-resistant epilepsy. AG is frequently localized in the supratentorial regions and only one patient is in the brainstem. Brain parenchyma atrophy, and stalk-like signs can observe in imaging. Pathologically, tumor cells are perivascular pseudorosettes, presenting immunoreactivity for GFAP, S-100, Vimentin, "dot-like" staining for EMA, and low proliferative activity. Focal cortex dysplasia was observed in four patients. Twelve of fourteen (85.7%) patients were found with MYB-QKI fusions. Completely surgical resection typically has a satisfactory prognosis with long-term follow-up.

Conclusion: AG is a rare benign tumor with a favorable prognosis after complete resection, characterized by refractory epilepsy, frequently occurring in adolescents. MYB-QKI fusions were detected in most AG patients, as a good defining genetic alteration pathologically. The potential presence of focal cortical dysplasia (FCD) may affect the prognosis of epilepsy.