10085- BT-4 MEDULLOBLASTOMA WITH INTRATUMORAL HEMORRHAGE

Abstract INTRODUCTION Medulloblastoma, a malignant pediatric brain tumor, is classified into four molecular subtypes: WNT, SHH, Group 3, and Group 4, according to the 2021 WHO classification. Reports indicate that WNT-type medulloblastomas have a higher incidence of intratumoral hemorrhage compared to other subtypes. This study investigates the correlation between intratumoral hemorrhage and molecular classification in medulloblastoma cases treated at our institution, supplemented by a literature review. METHODS We included patients diagnosed with medulloblastoma from January 2011 to July 2024. Intratumoral hemorrhage was identified using CT and MRI, and molecular diagnoses along with clinical findings were retrospectively reviewed and evaluated. RESULTS The study comprised 21 medulloblastoma cases with an average age of 12.2 years and a male-to-female ratio of 3:2. The molecular subtypes included 7 WNT, 5 SHH, 1 Group 3, and 7 Group 4. Intratumoral hemorrhage was observed in 3 cases, all of which were WNT-type. The average age of WNT-type cases was 10.1 years, with a male-to-female ratio of 4:3. There were no significant differences in treatment outcomes between hemorrhagic and non-hemorrhagic cases. DISCUSSION WNT-type medulloblastomas may cause blood-brain barrier dysfunction due to β-catenin mutations, leading to intratumoral hemorrhage. Our findings support previous reports showing a higher incidence of intratumoral hemorrhage in WNT-type medulloblastomas. Hemorrhagic medulloblastomas on imaging are likely WNT-type, making intratumoral hemorrhage an important factor in treatment strategy planning. CONCLUSION Our analysis of medulloblastoma cases at our institution confirmed a significantly higher incidence of intratumoral hemorrhage in WNT-type tumors. Intratumoral hemorrhage can aid in preoperative molecular diagnosis of medulloblastomas.