Pediatric Spinal Cord Astrocytoma With Granular Cell-Like Morphology and KIAA1549::BRAF Fusion.

We report a pediatric spinal cord tumor with prominent granular cell-like features that posed a significant diagnostic challenge. Intraoperative findings and the initial histopathological evaluation revealed marked granular cell proliferation, leading to a provisional diagnosis of granular cell astrocytoma. Notably, the classical histological features of pilocytic astrocytoma (PA) were not evident. However, molecular profiling identified a KIAA1549::BRAF fusion, prompting diagnostic reconsideration. Re-evaluation of the histopathological findings in conjunction with the molecular results supported an integrated diagnosis consistent with PA. This case highlights the marked morphological variability of PA and demonstrates that pediatric spinal circumscribed astrocytic gliomas with granular cell-like morphology may closely mimic granular cell tumors or granular cell astrocytomas. Our findings underscore the important complementary role of molecular genetic analyses, particularly the assessment of BRAF alterations, in supporting diagnosis and guiding appropriate therapeutic decision-making in diagnostically challenging pediatric spinal cord tumors.