A Phase II Study of Perifosine in Patients With Relapsed/Refractory Waldenström's Macroglobulinemia

Inclusion Criteria: * Age \>= 18 years. * Must have received prior therapy for their WM and have relapsed or refractory WM. Any number of prior therapies is acceptable. * Measurable disease, defined as presence of immunoglobulin M (IgM) paraprotein with a minimum IgM level of \> 2 times the upper limit of each institution's normal value is required and over 10% of lymphoplasmacytic cells in the bone marrow. * ECOG Performance Status (PS) 0, 1, or 2. * The following laboratory values obtained 14 days prior to registration * ANC \>= 1 x109/L * PLT \>= 75 x109/L * Total bilirubin ≤ 2.0 mg/dL (If total is elevated check direct and if normal patient is eligible.) * AST \<= 3 x upper limit of normal (ULN) * Creatinine \<= 2 x ULN * Ability to provide informed consent. * Life expectancy \>= 12 weeks. Exclusion Criteria: * Uncontrolled infection. * Other active malignancies. * CNS involvement. * Cytotoxic chemotherapy ≤ 3 weeks, or biologic therapy ≤ 2 weeks, or corticosteroids ≤ 2 weeks, prior to registration. Patients may be receiving chronic corticosteroids if they are being given for disorders other than WM such as auto-immune diseases. Plasmapheresis is not considered as an active therapy and can be used at the physician's discretion. * Other concurrent chemotherapy, immunotherapy, radiotherapy, or any ancillary therapy considered investigational. * Any of the following: * Pregnant women * Nursing women * Men or women of childbearing potential who are unwilling to employ adequate contraception (condoms, diaphragm, birth control pills, injections, intrauterine device (IUD), or abstinence, etc.) * Known to be HIV positive. * Radiation therapy ≤ 2 weeks prior to registration.