DISSEMINATED SUPERFICIAL POROKERATOSIS DEVELOPING AFTER ELECTRON-BEAMTOTAL SKIN IRRADIATION FOR MYCOSIS-FUNGOIDES

A 74-year-old man with stage IB cutaneous T-cell lymphoma was treated with electron-beam total skin irradiation in 1988. Seven years later, multiple disseminated lesions of porokeratosis developed on the chest, extremities and abdomen. There was no family history of porokeratosis , nor history of treatment with PUVA or of excessive sun exposure. Dev elopment of disseminated porokeratosis on nonexposed sites suggests a direct role for the previous ionizing radiation. Electron-beam total s kin irradiation therapy should therefore be added to the list of possi ble causative factors in the development of disseminated porokeratosis .