A Rare Case of Intramedullary Juvenile Xanthogranuloma of the Cervical Spine in an Adult: Cytological Features Aiding Diagnosis

Juvenile xanthogranuloma (JXG), the most common non-Langerhans cell histiocytosis (non-LCH), typically manifests as a benign cutaneous condition in children but is rare in adults, with extracutaneous cervical spine involvement being uncommon. To the best of our knowledge, we present the first case of intramedullary cervical spinal JXG in a 39-year-old man with persistent right upper extremity numbness. MRI identified a lesion at C3-C4, and surgical resection revealed a 7-mm yellow-whitish nodule. Histopathology demonstrated foamy histiocytes, multinucleated giant cells, and inflammatory infiltrates, with immunohistochemistry positive for CD68, CD163, and vimentin, and negative for CD1a and S-100 protein, distinguishing it from LCH. Cytopathology was instrumental, revealing low cellularity, mononuclear histiocytes, and CD68-positive granules, offering definitive diagnostic precision in this rare presentation. This case underscores cytopathology's critical role as an essential tool in accurately diagnosing atypical JXG manifestations.