Rosette-forming glioneuronal tumor of the cerebellum with intratumoral hemorrhage: case report with radiologic-pathologic correlation in a resource-limited setting.

BACKGROUND: Rosette-forming glioneuronal tumor (RGNT) is a rare, low-grade glioneuronal neoplasm of the posterior fossa, most commonly affecting children and young adults. Although typically indolent, its variable clinical and radiologic presentation may pose diagnostic and management challenges.

CASE REPORT: The present case is that of a 19-year-old woman who presented with headache and vomiting and was found to have a hemorrhagic, multicystic lesion centered on the right cerebellar peduncle. Serial radiological imaging demonstrated lesion persistence and stability over a period of more than 12 months, prompting surgical debulking. Histopathologic examination revealed a biphasic glioneuronal tumor composed of true neuropil-centered neurocytic rosettes within a fibrillary glial background. Immunohistochemistry revealed synaptophysin positivity within the rosette cores, glial fibrillary acidic protein (GFAP) expression confined to the glial component, and a low proliferative index (< 1%), meeting the World Health Organization (WHO) essential diagnostic criteria for RGNT, CNS WHO grade 1. Molecular testing was not performed.

CONCLUSION: This case illustrates the diagnostic value of integrated clinical, radiologic, and pathologic assessment in establishing a confident diagnosis of RGNT, even in the setting of atypical hemorrhagic presentation. Recognition of classic morphologic and immunophenotypic features remains central to accurate diagnosis and appropriate management, particularly in resource-limited settings where access to molecular testing is limited.