Isolated calvarial aneurysmal bone cyst in a pediatric patient: illustrative case.

BACKGROUND: Aneurysmal bone cysts (ABCs) are benign, osteolytic lesions that can occur in long bones, vertebrae, or rarely, the skull. Here the authors present the case of a 15-year-old male with a primary ABC of the left frontoparietal skull along with a review of the literature to provide insight into the nature of this rare disease. OBSERVATIONS: An otherwise healthy 15-year-old male presented with a tense, painful lesion of the left frontoparietal scalp. He could not identify any inciting trauma, but first noted the lesion less than 2 weeks prior to presentation with progressive enlargement. Cranial imaging revealed a lytic skull lesion with fluid-fluid levels suggestive of ABC. Curative therapy was provided via wide excision of the lesion and calvarial reconstruction of the resultant skull defect. This was performed without complication, and histopathological evaluation confirmed the diagnosis of primary ABC. LESSONS: ABCs of the skull are rare entities and most often arise in the skull base versus the calvaria. Typically, these lesions are associated with an underlying bone pathology (secondary ABCs) but can be rarely seen as isolated lesions (primary ABCs). Clinical management consists of excision and adjuvant therapy for underlying pathology where appropriate.

Mutations in chromatin machinery and pediatric high-grade glioma.

Pediatric central nervous system tumors are the most common solid tumor of childhood. Of these, approximately one-third are gliomas that exhibit diverse biological behaviors in the unique context of the developing nervous system. Although low-grade gliomas predominate and have favorable outcomes, up to 20% of pediatric gliomas are high-grade. These tumors are a major contributor to cancer-related morbidity and mortality in infants, children, and adolescents, with long-term survival rates of only 10 to 15%. The recent discovery of somatic oncogenic mutations affecting chromatin regulation in pediatric high-grade glioma has markedly improved our understanding of disease pathogenesis, and these findings have stimulated the development of novel therapeutic approaches targeting epigenetic regulators for disease treatment. We review the current perspective on pediatric high-grade glioma genetics and epigenetics, and discuss the emerging and experimental therapeutics targeting the unique molecular abnormalities present in these deadly childhood brain tumors.