A rare case of paediatric cerebellar neurocytoma with conflicting histologic features of medulloblastoma – diagnostic and management challenges

Abstract

Abstract Background Cerebellar neurocytoma is an exceptionally rare central nervous system tumour, often misdiagnosed due to its histologic overlap with medulloblastoma, a more common and aggressive paediatric brain tumour. Only four cases of paediatric cerebellar neurocytoma has been documented so far. This case report aims to highlight the diagnostic and management challenges in differentiating these two entities, emphasizing the importance of comprehensive histopathological, immunohistochemical, and radiological analysis to guide appropriate treatment strategies. Case description An 8-year-old boy presented with a cerebellar tumour initially diagnosed as a cerebellar neurocytoma (WHO grade 2) based on histologic findings of uniform small to medium-sized cells, low mitotic activity, and absence of necrosis. Following surgical resection, the tumour recurred eight months later, exhibiting features suggestive of medulloblastoma (WHO grade 4), including densely packed undifferentiated cells, necrosis, and Homer-Wright rosettes. Immunohistochemistry confirmed neurocytoma, with positivity for neuron-specific enolase (NSE) and synaptophysin, and a low Ki67 index (< 2%). Advanced imaging and histologic correlation were critical in resolving the diagnostic dilemma. Conclusion This case underscores the diagnostic challenges in distinguishing cerebellar neurocytoma from medulloblastoma due to overlapping histologic and radiological features. Accurate diagnosis is essential, as these tumours have distinct WHO grades, prognostic implications, and treatment approaches. Comprehensive immunohistochemical analysis and advanced imaging techniques are vital for guiding appropriate management and improving patient outcomes.