Intralesional interferon in the treatment of early mycosis fungoides.

Twelve patients with early mycosis fungoides were enrolled in a randomized, double-blind, placebo-controlled study. Isolated plaques were injected three times a week with recombinant alpha 2-interferon in nine patients and with the vehicle in three patients. Two additional plaques were evaluated in each patient; one was left untreated, and another was treated topically with either placebo ointment or betamethasone ointment. Biopsies were taken from an untreated, representative plaque prior to treatment and from all test sites following treatment for light microscopy and T lymphocyte subsets. Three of the nine lesions injected with interferon cleared, and all showed improvement. Thirteen of eighteen noninjected lesions improved in patients who received interferon, showing a systemic effect. In the control group, none of the injected lesions improved and only two of the noninjected lesions showed any change. Histopathologic changes confirmed the clinical impression. This study shows that intralesional interferon may be given safely and has a beneficial effect, both locally and systemically.