[Bing-Neel syndrome: 3 cases report and a review of the literature].

Objective: To evaluate the clinical characteristics, diagnosis criteria, treatment and prognosis in patients with Bing-Neel Syndrome (BNS) . Methods: The clinical characteristics, lab data, treatment and outcomes of 3 Bing-Neel syndrome patients diagnosed at Peking Union Medical College Hospital were collected. Results: The clinical presentation was heterogeneous without any specific common signs or symptoms. One patient was diagnosed with BNS 42 months after diagnosis of Waldenström macroglobulinemia (WM) by cerebrospinal fluid (CSF) cytology and flow cytometry, but dead of infection during the first course of chemotherapy. BNS was the first manifestation of WM in the other 2 cases. They were diagnosed by flow cytometry and cytology of CSF. The detection of MYD88(L)265P mutation in CSF contributed to diagnosis and to sequential monitoring of minimal residual disease. They received systemic chemotherapy of FC (fludarabine + cyclophosphamide) ± rituximab and intrathecal therapy, followed by maintenance therapy of chlorambucil or R2 (rituximab + lenalidomide) . They were followed 17 and 20 months respectively without progression of disease. Conclusion: The diagnosis approach of BNS should be based on a combination of CSF cytology, flow cytometry and detection of the MYD88(L265P) mutation. The detection of MYD88(L265P) mutation may be useful in the monitoring of minimal residual disease.