Cutaneous T-cell lymphoma (CTCL) is a dynamic disease with several distinct components that make it unique from other lymphomas. The components of CTCL are reviewed to provide a background for understanding the role of pentostatin (Nipent; SuperGen, San Ramon, CA) in CTCL. In CTCL the malignant T cells mimic and eventually replace their nonmalignant counterparts. This enhances the need for targeting T cells with therapy that preferentially eliminates CTCL cells while sparing nonmalignant cells. Given the similarities of CTCL with T-cell mediated chronic inflammatory diseases, therapies used for this lymphoma also may play a role in nonmalignant disease management.