Diffuse midline glioma of spinal cord with H3K27M-mutation: a clinicopathological analysis

Abstract

Objective To investigate the role of H3K27M mutant in spinal cord glioma, specifically the correlation between H3K27M mutation and histological grade or prognosis. Methods Twenty-four cases of paraffin-embedded spinal cord glioma tissues and clinical data were collected from November 2014 to August 2016 at the Beijing Tsinghua Changgung Hospital. There were 13 males and 11 females, and the age ranged from 3 to 66 years. All the cases were reviewed histologically, and immunohistochemical H3K27M staining and H3 gene detection were performed. The correlation between H3 gene mutation and histological grading and prognosis of spinal cord gliomas were investigated and relevant literature reviewed. Results Eleven of 24 cases showed H3K27M gene mutation, and was concordant with the result of immunohistochemistry. Gliomas in the mutant group were all high-grade gliomas with mean patients′ age of (30.0±11.5) years, and a male to female ratio of 7:4. Thirteen cases were wild-type, and these included four high-grade gliomas, with mean patients′ age (31.3±22.4) years, and a male to female ratio of 6∶7. The tumors in the mutant group were mainly located in cervical 4-7 and thoracic 11-12 segments, respectively, and the incidence of tumors in the lower thoracic segments (thoracic 11-12) was higher than that in the wild type group. Outcome data were available for all patients. The median survival of mutant group was 19.5 months, but most patients in the wild-type group were alive at the end of the follow-up period. Conclusion Gliomas of spinal cord with H3K27M mutation are high-grade and the prognosis of patients is poor. Key words: Spinal cord neoplasms; Glioma; DNA mutational analysis; H3K27M-mutation