Extraneural metastases of a cerebral glioma in a child: case report with literature review

Abstract

Malignant gliomas make up 25 % of the central nervous system (CNS) tumors in adults and 8–15 % in children. About half of such gliomas have a median localization and are designated by the term "diffuse midline gliomas" (DMG). DMG in children are typically localized in the area of the pons; in 78 % of such cases a heterozygous somatic mutation H3K27M is present. The prognosis of H3K27M-mutant DSG is very unfavorable, with 2-year overall survival rate being less than 10 %. One of the ways of progression of gliomas leading to the death of patients is the spread of the tumor in the form of metastases. Malignant gliomas metastasize mainly into various structures of the CNS (according to autopsies – in about 20 % of patients with glioblastomas), the probability of their metastases to other organs (so-called extraneural metastases), according to some evaluations, is quite rare and doesn’t exceed 2 %. In our practice since 1993, which counts 1700 children with malignant gliomas, including 830 patients with DMG, we’ve observed only one patient with extraneural metastases. The article describes this case of a child who died of the progression of the DMG’s extraneural metastases, despite the fact that chemoradiotherapy had achieved its stabilization in the CNS. This patient with the initial lesion of the pons and cerebellum had massive metastasis to the lymph nodes: supraclavicular, mediastinal, retroperitoneal and inguinal ones, as well as to both pleural cavities, which occurred about one year after treatment of the progression, which had manifested in the form of continued growth of the primary tumor and its dissemination in the central nervous system. The article provides literature data on the frequency, clinical manifestations and possible treatment approaches for extraneural metastasis of brain gliomas. Extraneural metastases of those tumors occur most often to the bones, lymphatic system, lungs, abdominal organs, soft tissues. The effective treatment for extraneural metastases of gliomas has not been developed yet, which makes it urgent to solve this problem through multicenter studies.

Keywords

• malignant glioma
• brain
• extraneural matastases
• radiotherapy
• chemotherapy