Leptomeningeal (LM)
metastases or dural spread by adult high-grade
astrocytomas are problematic; it is unclear which
tumor types are predisposed to spread and at what time intervals from original diagnosis. We reviewed our recent experience with these
tumor types with LM or dural spread, all of which had assessments that allowed CNS World Health Organization, 5th Edition classification. Following a database search, 2018-present, 10 patients were identified: 4
glioblastomas, IDH-wildtype, WHO grade 4; 4
astrocytomas, IDH-mutant, WHO grade 4; 1 high-grade
astrocytoma with piloid features (
HGAP) proven by DNA methylation, and 1 high-grade astrocytic
tumor that fell closest to the
HGAP category by DNA methylation. Most had LM dissemination; 2 had dural spread. Intervals from initial
tumor diagnosis to LM spread for 4
astrocytomas, IDH-mutant were 1, 6, 7, and 14 years. Two
glioblastomas, IDH-wildtype had dural spread at the time of diagnosis; 1 had a 6-year interval to
metastasis; and 1 had a 3-month interval to LM spread. The definite
HGAP showed an interval of 7 years to
metastasis and the possible
HGAP had LM spread recognized at the time of initial diagnosis. All adult high-grade astrocytic
tumor types are capable of LM or dural spread, including
HGAP.