Recurrent central nervous system Rosai-Dorfman disease with KRAS mutation: a case report.

BACKGROUND: Rosai-Dorfman disease (RDD) is a rare, non-Langerhans cell histiocytosis of unknown etiology. we report a very rare case of recurrent central nervous system RDD with KRAS gene mutation and review the literature to improve our understanding of this disease.

CASE PRESENTATION: A 19-year-old male patient was admitted to our hospital for headache. Cranial magnetic resonance imaging revealed a mass of abnormal signal shadows in the prepontine cistern. The mass was surgically removed and the patient was consequently diagnosed with intracranial Rosai-Dorfman disease. Seven months later, pathological examination confirmed that the RDD had recurred. Next-generation sequencing found KRAS mutation in exon 4 (C.351A > C. P. K117n).

CONCLUSION: RDD of the CNS has no distinct clinical manifestations and imaging characteristics, and the final diagnosis should be based on the results of the pathological examination. Although RDD is not currently classified as a neoplastic disorder, some evidence of clonality has changed our understanding of it. Follow up examinations over a long period are necessary to determine the efficacy of treatment.