2nd Autologous Stem Cell Transplant in Patients With Persistent/Recurrent (AL) Amyloidosis

RATIONALE: Drugs used in chemotherapy work in different ways to stop the growth of plasma cells, either by killing the cells or by stopping them from dividing. Having a stem cell transplant to replace the blood-forming cells destroyed by chemotherapy, allows higher doses of chemotherapy to be given so that more plasma cells are killed. By reducing the number of plasma cells, the disease may progress more slowly. PURPOSE: This phase II trial is studying how well autologous stem cell transplant works in treating patients with persistent or recurrent primary systemic (AL) amyloidosis.