UNASSIGNED: Rosai-Dorfman disease is a rare, histiocytic lymphoproliferative disease of unknown etiology. It manifests mainly as painless cervical lymphadenopathy, with very few cases reported extranodal involvement in the central nervous system. Isolated spinal Rosai-Dorfman disease is sporadic.
METHODS: This case report documents a rare instance of an isolated long-segment spinal Rosai-Dorfman disease (C4-D6) along with the review of relevant literature. A 33-year male presented with progressive quadriparesis and urinary retention. A magnetic resonance scan (MRI) revealed a long segment epidural lesion from C4-D6 levels that led to the displacement of the cord. A core biopsy of the spinal tumor revealed characteristic histiocytic emperipolesis and confirmational immunocytohistochemistry markers, confirming the diagnosis. Surgical resection and laminoplasty were performed.
UNASSIGNED: The following histopathology and immunocytohistochemistry findings showed the presence of histiocytes positive for S100 and CD68 positive. Therefore, it was diagnosed to be a case of Rosai-Dorfman disease. The patient had a smooth postoperative recovery and displayed marked motor improvement in the ensuing days. This is a rare case that posed an intriguing challenge to approach.
CONCLUSIONS: To our knowledge, we have encountered one of the most prolonged segmental lesions in isolated spinal Rosai-Dorfman diseases, where surgical management (surgical resection and laminoplasty) has proven to bring about remarkable improvement.

We report five patients in whom spinal MRI revealed extra-arachnoid fluid collections. These spinal fluid collections most likely resulted from accumulation of cerebrospinal fluid (CSF) from a dural leak. The patients presented with either compressive myelopathy due to the cyst or superficial siderosis (SS). All of these fluid collections were long segment, and MRI demonstrated the fluid collections but not the exact site of leak. Dynamic CT myelogram demonstrated the site of leak and helped in the management of these complicated cases. Moreover, we also found that the epicenter of the fluid collection on MRI was different from the location of the leak on a dynamic CT myelogram. Knowledge of these associations can be helpful when selecting the imaging studies to facilitate diagnosis and treatment.