Clinical manifestations of, diagnostic approach to, and treatment of neurolymphomatosis in the rituximab era.

Neurolymphomatosis (NL) is a rare manifestation of lymphoma, with limited evidence for optimal management. The largest patient series, 50 cases of lymphoma and leukemia, was published in 2010 with limited rituximab exposure. This study aims to evaluate the clinical presentation, diagnostic testing, and outcomes of NL in the rituximab era. Forty biopsy-proven cases of NL, in association with non-Hodgkin lymphoma (NHL), at the Mayo Clinic were retrospectively evaluated. B-cell NHL was associated with 97% of NL cases, of which diffuse large B-cell lymphoma (DLBCL) was the most common (68%). Primary NL, defined as neural involvement present at the time of diagnosis of lymphoma, was noted in 52% cases. Seventy percent of patients presented with sensorimotor weakness and neuropathic pain. Magnetic resonance imaging (MRI) was positive in 100% patients. Overall survival (OS) was significantly better for primary NL and NL associated with indolent lymphomas. Relapses were seen in 60% (24/40) of patients; 75% involved the peripheral or central nervous system at relapse. The use of rituximab in the frontline setting significantly impacted progression-free survival (PFS). Transplant consolidation was noted to be associated with improved OS. This study adds to the available literature on NL in the rituximab era. The overall outcomes have improved in recent years. In our experience, MRI and positron emission tomography/computed tomography may be required for accurate assessment of the extent of disease involvement and identification of an optimal biopsy site. The use of rituximab was associated with improvement in PFS, and autologous stem cell transplant was associated with OS.