"Diffuse brainstem gliomas or diffuse intrinsic pontine gliomas was a term used to describe infiltrating astrocytomas arising in the brainstem, usually in children. It is no longer recognised as a distinct entity, removed from the 2016 update to the WHO classification of CNS tumours replaced by a variety of entities defined on the basis of molecular characteristics. The majority of these tumours would now be classified as diffuse midline glioma, H3 K27M–mutant which, for the sake of clarity, are described separately."
"As of the 2016 update to the WHO classification of CNS tumours, these have been given a distinct and separate diagnosis: diffuse midline glioma, H3 K27M–mutant."
"As of the 2016 update to the WHO classification of CNS tumours, diffuse intrinsic brainstem glioma (DIBG) has been removed and diffuse midline glioma, H3 K27M–mutant has been added as a specific entity 6."
"Due to the high rate of severe complications with biopsy treatment has historically been commenced without histological confirmation, although due to the identification of distinct mutations (see diffuse midline glioma H3 K27M–mutant) stereotactic biopsy is being performed in some centres, and is becoming more common as therapies specifically targeted to these mutations become available 5."
"NOTE: The remainder of this article is therefore largely of historical relevance only."
"T1: decreased intensity"
"T2:"
"T1 C+ (Gd):"
"DWI/ADC:"
"T2*/SWI: areas of marked hypointensity/blooming in cases of intralesional haemorrhage8"
"Epidemiology "
"Clinical presentation "
"Usually, the tumour is homogeneous pre-treatment, however, in a minority of patients areas of necrosis may be present."
"enhancement may occur post-radiotherapy"
"T2*/SWI: areas of marked hypointensity/blooming in cases of intralesional haemorrhage8"
"NOTE: The remainder of this article is therefore largely of historical relevance only."
"NOTE: The remainder of this article is therefore largely of historical relevance only."
"Genomic work has uncovered distinct mutations found in the majority of diffuse midline gliomas, particularly diffuse intrinsic pontine gliomas (DIPG). These mutations are in the histone H3F3A gene (K27M mutations) or less frequently HIST1H3B and HIST2H3C genes 5,6."
"Langerhans cell histiocytosis"
Expected headings
"Epidemiology "
"Clinical presentation "
"It has become apparent that a large proportion of these tumours (particularly diffuse intrinsic pontine gliomas) harbour K27M mutations in the histone H3 gene H3F3A, or, less commonly, in the related HIST1H3B genes. These mutations are shared by other midline paediatric tumours (e.g. thalamic and spinal cord tumours)."
"There is an association with neurofibromatosis type I, which however carries a better prognosis with a more indolent course."
"Typically patients present with multiple cranial nerve palsies, depending on the location of the tumour, and signs of raised intracranial pressure. Cerebellar signs may also be elicited including ataxia, dysarthria, nystagmus and sleep apnoea."