Rosai-Dorfman disease with spinal cord compression: a diagnostic challenge.

Purpose: Rosai-Dorfman disease (RDD) is an uncommon benign histiocytic proliferative disorder commonly involving the cervical lymph nodes and less frequently extranodal sites, including, rarely, the central nervous system, mainly intracranially. Spinal involvement is unusual. RDD is characterized by pathognomonic histopathological features, which are decisive in the definitive diagnosis. We present the case of a 75-year-old lady who presented with an isolated thoracic vertebral lesion. She underwent 3 CT-guided biopsies, all not confirmative for a definite diagnosis, and 2 open biopsies and debulking of the lesion.

Methods: The clinical notes, operation notes, investigations and clinic letters of the patient were reviewed. A literature search was performed using PubMed, with the keywords "Rosai-Dorfman disease", "sinus histiocytosis with massive lymphadenopathy", "histiocytic proliferative disorder".

Results: Only the histopathology after the last procedure was diagnostic for Rosai-Dorfman disease. The patient was treated with steroids with marked improvement in her clinical condition.

Conclusions: This case demonstrates the challenge in making a diagnosis. RDD should be considered as a differential diagnosis in case of spinal lesion and non-diagnostic biopsy, especially in steroid sensitive lesions. The implications of the case are discussed.