Isolated cerebellar intraparenchymal Rosai-Dorfman disease--case report and review of literature.

BACKGROUND: Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy) rarely affects intracranial structures without involvement of other sites. We herein review the tumour characteristics, differential diagnosis and treatment policy of this rare disease.
METHOD: We conducted a PUBMED search using a combination of words 'Rosai-Dorfman disease', 'Central nervous system', and identified 42 cases of such a disease infecting exclusively central nervous system. Out of those cases only one case was reported to be purely intracerebellar making our case the second one in the literature. Clinical features, differential diagnosis, treatment details and follow-up were discussed. We also described the case of 41-year-old man presented with vertiginous symptoms and mild cerebellar ataxia who was diagnosed with a solitary lesion localised deep in the right cerebellar hemisphere. Immunohistological findings revealed Rosai-Dorfman disease.
FINDINGS: The most common locations of the tumour were frontal and parietal region, but CNS lesions have commonly involved the skull base with a leptomeningeal component too. The median age at presentation was in the third decade, ranging from 3 to 78 years. There is a slight male predominance. The follow-up ranged from 1 month to 11 years. Recurrence was not observed in the cases where total surgical excision was performed.
CONCLUSION: Though Rosai-Dorfman disease is a rarity, one should take it into a consideration when treating solitary intracerebellar lesion. Thorough preoperative evaluation is mandatory and biopsy should be done whenever feasible. Surgical treatment of this type of tumour is not always necessary, however, it is essential for postulating the right diagnosis. When total tumour removal is achieved, the outcome is generally better, with minimal risk of recurrence and with no need for further additional therapy.