Bing-Neel Syndrome with Detectable MYD88 L265P Gene Mutation as a Late Relapse Following Autologous Hematopoietic Stem Cell Transplantation for Waldenström's Macroglobulinemia

Primary central nervous system diffuse large B-cell lymphoma masqueraded as Bing-Neel syndrome: Steps in management and review of future directions

Bing-Neel syndrome (BNS) remains a rare complication of Waldenstrom Macroglobulinemia. Given the paucity of this disease, treatment guidelines are based on small clinical trials with limited participants. Here, we present a case of primary CNS diffuse large B-cell lymphoma masqueraded as BNS that developed while on ibrutinib therapy.

Effectiveness of digital PCR for MYD88L265P detection in vitreous fluid for primary central nervous system lymphoma diagnosis

Primary central nervous system lymphoma (PCNSL) is a rare type of primary extranodal lymphoma (PEL). MYD88^L265P mutation has been observed in up to 75% of PCNSL cases, however, the validity and sensitivity of digital PCR in detecting this mutation remains to be elucidated. A total of 44 PCNSL patients, 15 diffuse large B-cell lymphoma not otherwise specified (DLBCL-NOS) patients and 13 other PEL patients were enrolled in the present study. The abilities of reverse transcription quantitative PCR (RT-qPCR) and droplet digital PCR (ddPCR) to detect the MYD88^L265P mutation in cerebral spinal fluid (CSF) samples were compared. The results suggested that ddPCR showed superior mutation detection sensitivity when compared with RT-qPCR (58 vs. 15%; P<0.05). The MYD88^L265P mutation was significantly associated with increased MYD88 protein overexpression in PCNSL brain tissue samples (P<0.05). Analysis of MYD88^L265P mutation status in CSF and vitreous fluid samples using ddPCR may be a promising technique for minimally invasive confirmation of PCNSL diagnosis.

An Autopsy Case of Bing-Neel Syndrome: Discrepancy between the Radiological and Pathological Findings

A 64-year-old man previously diagnosed with Waldenstrom's macroglobulinemia presented to our hospital with confusion. Magnetic resonance imaging (MRI) revealed diffuse meningeal enhancement. The patient was diagnosed with Bing-Neel syndrome (BNS) based on an elevated IgM index and the presence of monoclonal IgM protein, as detected by immunofixation electrophoresis of the cerebrospinal fluid. The patient underwent intrathecal and systemic chemotherapy but ultimately died of pneumonia. An autopsy revealed extensive meningeal and perivascular infiltration by malignant cells throughout the brain and spine. Thus, BNS may cause more extensive malignant infiltration into the central nervous system than is revealed by MRI.