Paediatric diffuse leptomeningeal tumor with glial and neuronal differentiation harbouring chromosome 1p/19q co-deletion and H3.3 K27M mutation: unusual molecular profile and its therapeutic implications

We present a rare instance of a DL-GNT in a 13-year-old female who presented with slowly progressive and sequential neurological deficits over a 12-month duration. Imaging showed leptomeningeal thickening and spinal lesions. Biopsy from the spinal mass showed histomorphological features characteristic of DL-GNT. Further molecular analysis revealed 1p and 19q co-deletion andH3K27M mutation, while no mutation were identified inIDH, TERT, orBRAF genes. Patient died 4  months after diagnosis. Only one previous case of DL-GNT has been reported to harbourH3K27M mutation. AlthoughH3K27M mutations have been described in rare examples of low-grade glial and glioneuronal tumors, whether DL-GNTs withH3K27M represent a rare growth pattern of the aggressiveH3K27M-mutant diffuse midline gliomas needs further clarification.
Source: Brain Tumor Pathology - Category: Neurology Source Type: research