Primary cerebellar angiosarcoma: A rare case of posterior fossa vascular tumor with hemorrhagic presentation and favorable surgical outcome

Primary cerebellar angiosarcoma is an exceptionally rare intracranial malignancy, with only 22 cases reported in the literature. We report the case of a 67-year-old male who presented with a severe headache, unsteady gait, and giddiness. Computed tomography of the brain demonstrated a hemorrhagic lesion in the right cerebellar hemisphere with associated vasogenic edema and early hydrocephalus. Magnetic resonance imaging revealed a right cerebellar intra-axial lesion with mixed signal intensities and a characteristic peripheral "bull's eye" enhancement pattern. Histopathological evaluation showed a vasoformative neoplasm with atypical endothelial cells, high mitotic activity, and immunopositivity for CD31 and erythroblast transformation specific (ETS)-related gene (ERG), consistent with low-grade angiosarcoma. The patient underwent gross total resection and remained recurrence-free 16 months postoperatively. This case underscores the importance of multi-modality imaging in the early recognition of hemorrhagic cerebellar tumors and reinforces the role of radiological-pathological correlation in diagnosis and treatment planning. Given its rarity, diagnosis of cerebellar angiosarcoma requires a high index of suspicion, supported by advanced imaging and immunohistochemical profiling. Multidisciplinary management is essential, and further case documentation is necessary to guide therapeutic strategies and prognostication.