Bing Neel Syndrome: Retrospective Australasian Experience of a Rare Treatable Complication of Waldenström Macroglobulinaemia/ Lymphoplasmacytic Lymphoma
Authors: Talaulikar Dipti , Cochrane Tara , Gibson John , Hamad Nada , Ho Phoebe Joy , Issa Samar , Fiona Kwok , Lim Jun Hee , Simpson David , Tam Constantine , Castillo Jorge J. 
Published: October 2019

Abstract
Introduction and aims:Bing Neel syndrome (BNS) is a rare complication of Waldenström Macroglobulinaemia (WM)/ Lymphoplasmacytic Lymphoma (LPL). It is a clinicopathological entity characterised by central nervous system involvement with malignant cells. It presents with diverse symptoms and can be difficult to recognise. However, it is a treatable condition amenable to systemic and intrathecal treatment. We present the Australasian experience of this rare entity.
Methods:Inclusion in the study was based on cytologically or histologically confirmed presence of lymphoplasmacytic cells in the CSF or brain biopsy. Ten patients were included from 9 sites in Australia and New Zealand. Relevant retrospective data was extracted after obtaining consent from patients or next of kin.
Results: Seven of the 10 patients were males with overall mean age of 63.5 years (range: 49-78 years); 4 patients were < 60 years old. Four patients (40%) did not have a prior diagnosis of WM; the remaining 6 patients were diagnosed ~ 11 years post diagnosis of WM (range: 3 -26 years) and received 1 line of treatment (except for 2 patients who received 2 lines of treatment). Treatment regimens received included R-CVP, chlorambucil-prednisolone, DRC, FCR, oral fludarabine, and RFM.
At diagnosis of BNS, IgM and/or PP levels ranged between 3 - 70 g/L with 6 (60%) patients having levels < 10 g/L. One patient had a diagnosis of lymphoplasmacytic lymphoma with IgG paraprotein.
Symptoms at presentation of BNS varied from headache, ptosis/ophthalmoplegia, memory loss, subacute hemiplegia, cognitive defects, hearing loss, and sensory or motor neuropathy. None of the patients had B symptoms. Lymphadenopathy was noted in 4 (40%) cases, splenomegaly in 1 (10%) and ECOG performance status ranged from 0-4 with 3 (30%) patients having an ECOG of > 2.
Brain +/- spine MRI was done in all cases with 5 (50%) showing leptomeningeal involvement. Orbital infiltration or enhancement of optic or ophthalmic nerves was noted in 3 cases (30%), and 3 patients (30%) had focal signs/masses. 1 had cortical atrophy, and 3 had normal MRI. CSF analysis was abnormal in all cases on cytology with demonstration of abnormal lymphocytes. Where immunophenotyping was performed, it showed presence of CD5, CD10 negative B cells. MYD88 L265P was detected in 3 patients (30%).
Treatment of BNS included systemic chemoimmunotherapy in 30%, CNS penetrating intravenous agents in 40%, Ibrutinib in 50%, intrathecal chemotherapy in 30%, and radiotherapy in 10%. More than 1 modality of treatment was used in 40% of patients. Ibrutinib was administered as frontline treatment in combination with high dose MTX or IT chemotherapy in 3 patients, and as single agent monotherapy in 1 patient. Ibrutinib was used as second line treatment in 2 patients with both achieving CR. The number of cycles administered were 2.6 (range 1-9).
Response data was available in 9 patients with ORR in 6 (1 CR, 5 PR) and non-response in 3. All patients except the one treated with Ibrutinib monotherapy had at least PR. With a median follow-up time of 20 months, 3 patients have died. The median overall survival of patients was not reached. The 1-year and 3-year OS rates were 80% (95% CI 41-95%) and 60% (16-87%), respectively (Figure 1).
Conclusion:BNS should be suspected in WM patients who develop focal or nonspecific neurological symptoms. It can be readily diagnosed on radiological scans i.e. brain and spinal MRI, and/or on CSF analysis. It can be treated with a number of systemic and intrathecal drugs including Ibrutinib, which crosses the blood brain barrier.
Fig 1 legend:Kaplan Meir curve demonstrating median overall survival of patients (not reached) and 1-year and 3-year OS rates of 80% (95% CI 41-95%) and 60% (16-87%), respectively.

Disclosures
Talaulikar: Takeda: Research Funding; Novartis: Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria; Janssen: Honoraria, Speakers Bureau; Roche: Honoraria, Speakers Bureau. Ho:Celgene: Other: Travel to meeting ; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel to meeting; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Simpson:Roche: Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Acerta: Research Funding; Merck: Honoraria, Research Funding; BeiGene: Research Funding; Sanofi: Research Funding; Bristol-Myers Squibb: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Novartis: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; MSD: Honoraria; Abbvie: Honoraria, Research Funding; Amgen: Research Funding, TRAVEL, ACCOMMODATIONS, EXPENSES; Janssen: Honoraria, Research Funding. Tam:AbbVie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Beigene: Honoraria. Castillo:Pharmacyclics: Consultancy, Research Funding; Millennium: Research Funding; Janssen: Consultancy, Research Funding; Genentech: Consultancy; Beigene: Consultancy, Research Funding; Abbvie: Consultancy, Research Funding.