<unk>  (BNS) is an extremely rare neurologic complication of Waldenström macroglobulinemia (WM), which is a chronic lymphoproliferative disorder. There's no clear definition of BNS but what is known so far is that unlike WM, It involves the central nervous system (CNS), infiltrated by differentiated malignant B cells and by having hyperglobulinemia. This infiltration increases blood viscosity, which impairs blood circulation through small blood vessels of the brain and the eye. Some scientists proposed that a person diagnosed with BNS is typically classified into Group A and Group B depending on whether or not plasma cells are present within the brain parenchyma, leptomeninges, dura, and/or the cerebral spinal fluid (CSF). Symptoms are diverse and nonspecific, and they can vary depending on which aspect of the CNS is being affected. Symptoms can include a range of severity of nausea and seizures. Since the symptoms vary, there are multiple treatment options to treat the symptoms for this non-curable disease. Although there is no specific set of diagnosis for BNS, different combinations of diagnostic tools are used to narrow down and conclude the presence of BNS.
Bing–Neel syndrome
Hagemoser–Weinstein–Bresnick syndrome
SACRAL syndrome
VEXAS syndrome
Costeff syndrome
Melnick–Needles syndrome
POEMS syndrome
OSLAM syndrome