Extranodal Rosai-Dorfman Disease presenting as spinal extradural lesion: a case report with a review of the literature.

Sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai-Dorfman disease (RDD) is a rare, but well-documented entity. We report a male patient who presented with progressive paraparesis, with thoracolumbar extradural lesion (from D11 to L2 level) on magnetic resonance imaging (MRI). He underwent D12-L2 laminectomy followed by total removal of extradural spinal space-occupying lesion (SOL). Histopathological diagnosis of the lesion was RDD. Four weeks after surgery, he was treated with external beam radiotherapy, total dose: 50.4GY in 28 fractions. On three-month follow-up, he did not have any neurological deficits. There was no evidence of other extranodal or lymph node involvement. This case has been reported on account of rare presentation of this disease as spinal extradural lesion. Pertinent literature has been reviewed.