RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Photodynamic therapy uses light and drugs that make cancer cells more sensitive to light to kill cancer cells. Photosensitizing drugs, such as methoxsalen, are absorbed by cancer cells and, when exposed to light, become active and kill the cancer cells. Combining chemotherapy with photodynamic therapy may be an effective treatment for cutaneous T-cell lymphoma.