Title : A rare presentation of rosai-dorfman disease involving the central nervous system
Abstract:
A 29-year-old gentleman diagnosed with Rosai-Dorfman disease (RDD) on corneal biopsy, 2 years ago, presented with fluctuating left-sided numbness, intermittent slurred speech, and urinary incontinence, progressively worsening over the past three months. Magnetic resonance imaging revealed diffuse T2-weighted/fluid-attenuated inversion recovery (T2W/FLAIR) hyperintensity associated with patchy nodular enhancement in the pons and left temporal lobe. In addition, there was an increased T2 signal in the left lateral cord from C2 through C4 without enhancement. The differential diagnosis included RDD causing central nervous system (CNS) manifestations, other histiocytoses (including Langerhan’s cell histiocytosis), Behçet syndrome, sarcoidosis, chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS), lymphoma, and other infectious causes of rhomboencephalitis. A left temporal lobe biopsy was performed, which showed an atypical histiocytic infiltrate, positive for CD68 and S100. GFAP and mutant IDH1p.R132H stains were negative ruling out a primary glial neoplasm. The history of RDD along with the current histopathological features, strongly favored the lesion to be a RDD of the central nervous system. It is common to see emperipolesis described as histiocytic engulfment of intact lymphocytes and plasma cells with RDD, but they may not be present as shown in the present case and are not pathognomonic and can infrequently be observed in other neoplastic or nonneoplastic conditions. Rosai-Dorfman disease is a systemic histiocytosis often characterized by lymphadenopathy, occasionally presents with intra-axial brain mass lesions, posing a diagnostic challenge due to its similarity to other brain conditions. Despite treatment with high-dose corticosteroids followed by whole-brain radiation, the disease progressed in this patient.
