AB061. Oligodendroglioma in a 10-year-old girl with history of mediastinal mass and radiotherapy: a case report.

Background: Oligodendroglioma is a part of diffusely infiltrating gliomas with poorly understood pathological aspect often manifesting histologic overlap among other intracranial tumors, though it only consisted 5% in total. Its occurrences among pediatric is a rare finding, constituted <1% of total brain tumors in the population, but with molecularly distinct properties to its adult version. Metachronous pediatric oligodendroglioma plus mediastinal mass is even more uncommon, as history of double primary tumor serves as a groundbreaking point in understanding individual pathology. This study reports a rare case of pediatric oligodendroglioma with history of mediastinal mass.

Case description: This study reports a rare case of pediatric oligodendroglioma with history of mediastinal mass. A 10-year-old female presented to our emergency department with altered consciousness level in the past couple of weeks, and progressively worsening for 3 days. Moreover, she withstands a yearlong headache, plus continuously worsens weakness on the left side of the extremities for 6 months, right sided weakness of face and visual disturbances appeared at least 4 months prior presentation; no seizures were observed. History of pericardial effusion due to mediastinal mass was also recorded in 3 years before with history of pericardial tapping, with cytology showed malignant lesion; with history of 5 times radiotherapy cycle for treatment purpose, and patient discontinued therapy due to loss of follow up. Non-contrast head computed tomography (CT)-scan observed a mix-density lesion on the frontotemporoparietal region with calcification. On magnetic resonance imaging (MRI), mix-intensity lesion was found suggesting a glioma lesion. Patient underwent removal of tumor, with gross tumor removal was achieved. Histopathology result of oligodendroglioma was found.

Conclusions: The management of pediatric oligodendroglioma in our case involves wide range of discipline to elaborate its interaction with prior metachronous mediastinal mass, and findings of double primary tumor should raise any suspicion for any tumor-related genetic mutations.