Waldenstrom's macroglobulinemia with peripheral neuropathy and favorable long-term treatment responses

Abstract

Abstract Rationale: Waldenstrom's Macroglobulinemia (WM), is a rare hematological disorder with an indolent course that affects about 1 in 1,000,000 people over the age of 50. The two cases presented here highlight the favorable responses to targeted therapies and that such responses may show a longer progression-free survival than the standard regimens for WM (Dexamethasone + Rituximab + Cyclophosphamide and Bendamustine + Rituximab). Patient concerns: We report 2 Filipino patients with WM presenting with symptoms of peripheral nerve involvement characterized by numbness, dysesthesia and weakness. Diagnosis: Serum immunoelectrophoresis showed distinct bands in IgM and Kappa light chain channels, indicative of IgM kappa monoclonal gammopathy. Bone marrow aspirate flow cytometry showed a B-lymphoid population, bright expression of Kappa light chain surface immunoglobulin, all consistent with a B-cell neoplasm. Interventions: The first case received Dexamethasone + Rituximab + Cyclophosphamide. The second case was successfully treated with Rituximab + Bendamustine. Outcomes: The first case achieved complete remission for 9 years. However, in the 10th year of follow-up, there was recurrence of peripheral nerve symptomatology, which prompted a repeat course Rituximab monotherapy, with favorable response. The second case was successfully treated with Rituximab + Bendamustine over a 3-year course. Lessons: To the best of our knowledge, WM presenting with peripheral neuropathy with a long progression-free survival as described in these patients have not been reported before. The two cases highlight the potentially favorable responses to targeted therapies. Though the possibility of developing recurrence cannot be discounted, favorable outcomes with the use of the standard chemotherapies could still be expected.