Characterization of pediatric non-hematopoietic tumor metastases to the central nervous system: A single institution review

Central nervous system (CNS) metastases represent a small portion of pediatric CNS neoplasms and data surrounding this condition with high morbidity is scarce. Single institutional archival institutional pathology records between 1999 and 2022 were searched for patients over 21 years old and younger with CNS, dura, cranial nerve, CSF, or leptomeningeal metastases; 41 cases were identified. We documented primary tumor types and locations, metastasis locations, types of invasion (direct extension vs distant metastasis), times from imaging or pathologic diagnosis to CNS involvement, and outcomes. Distant metastasis was the most common mechanism of metastasis (n = 32, 78%). Interval times to CNS metastasis varied by both tumor type and primary tumor location. In this cohort, osteosarcoma portended the shortest survival following CNS metastasis. This study highlights the diverse mechanisms and locations of CNS involvement in pediatric CNS metastases and illuminates a need for varied monitoring strategies when considering primary tumor type and anatomic location.