CLINICAL FEATURES, TREATMENT AND OUTCOME OF NEUROLYMPHOMATOSIS: SINGLE INSTITUTION EXPERIENCE

Abstract

Introduction: Neurolymphomatosis (NL) is a highly rare disorder defined as infiltration of peripheral nervous system by a lymphoproliferative neoplasm, both presented as the first manifestation of the malignancy (primary NL) or as a site of disease progression or relapse (secondary NL). Clinical features of NL and best approach are still widely unknown. Methods: We retrospectively reviewed clinical records of all histologically confirmed-NL, diagnosed and treated at the Hematology Department of Mayo Clinic in Rochester MN between January 2002 and December 2018. Results: Over a 16-year period 40 patients were diagnosed with NL. Primary and secondary NL were 18 (45%) and 22 (55%) respectively, with a median age of 60.5 years (range 37-83) and male sex 24/40 (60%). The majority had B-cell lymphomas (39/40 patients): 27/40 (60%) with diffuse large B-cell lymphoma (DLBCL) and only 1 case of T-cell lymphoma. The affected structures included peripheral nerves in 16/40 cases, spinal nerves (12/40), neural plexus (14/40), cranial nerves (4/40), cauda equine (6/40); multiple sites were involved in 13/40. 4/40 cases had brain involvement and cerebrospinal fluid (CSF) was positive in 7/29. NL clinical manifestations included muscular weakness (33/40 patients), sensory deficit (32/40), pain (28/40) and autonomic dysfunction (3/40). Magnetic resonance imaging (MRI) detected neural abnormalities in 35/36 cases (97%), CT imaging identified disease in 3/8 (37%) and FDG-PET scan was positive in 22/31 (71%); electromyography showed some grade of neuropathy in 28/29 cases. Treatment included systemic chemotherapy in 38/40 patients, containing high dose methotrexate (HD-MTX) in 26/40(65%) and rituximab in 20/40 (50%); 11/39 (28%) patients underwent consolidative autologous stem cell transplant; 4/40 received consolidative radiotherapy (RT) and 1/40 was managed with RT alone; intrathecal chemotherapy was infused in 1/40 cases; one patient with solely great auricular nerve NL involvement was cured with surgery only. Treatment efficacy evaluated by imaging and clinical improvement consisted with an overall response rate of 73% (27/37) with a 51% (19/37) rate of complete remission (CR); the rates of CR reached with HD-MTX regimens and other systemic treatments were 56% (13/24) and 42% (5/13) respectively. The median overall survival (OS) was 137.8 months with a 48-months OS 73%. A trend of longer survival rate for primary NL, although no statistically significance, was observed, with a 48-month OS of 94% vs 56% for secondary NL (p 0.134). (Figure 1) Keywords: extranodal lymphomas; immunochemotherapy; non-Hodgkin lymphoma (NHL).