Vorinostat After Stem Cell Transplant in Treating Patients With High-Risk Lymphoma

RATIONALE: Vorinostat may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth, and may stimulate the immune system to stop cancer cells from growing. PURPOSE: This phase I trial is studying the side effects and best dose of vorinostat after stem cell transplant in treating patients with high-risk lymphoma.