Response to Ibrutinib of a Refractory IgA Lymphoplasmacytic Lymphoma Carrying the MYD88 L265P Gene Mutation.

In 2014 a 66-year-old woman presented with anemia and an IgAk monoclonal spike. Bone marrow (BM) biopsy showed 80% lymphocytes and lymphoplasmacytoid cells. Computed Tomography (CT) scan documented neither adenopathy nor splenomegaly. Diagnosis of IgA lymphoplasmacytic lymphoma was made. After three lines of treatment, progressive disease with adenopathies, splenomegaly, and ascites were documented on a CT scan. Our patient developed thrombocytopenia, transfusion-dependent anemia, and clinical deterioration. We performed genetic studies of peripheral blood lymphocytes with the NGS approach. Given the identification of MYD88 L265P mutation, in February 2018 our patient started ibrutinib off-label. Hb and PLT improved from day +35. In July 2018 no ascites and 50% reduction of adenopathies and spleen were shown on a CT scan. In April 2019 the patient was still on ibrutinib with transfusion independence and good performance status.