5‐Aminolevulinic Acid‐Based Photodynamic Therapy for the Treatment of Two Patients with Extramammary Paget's Disease

Photodynamic therapy (PDT), which employs a combination of a tumor‐localizing photosensitizer and visible light, has been used in the treatment of extramammary Paget's disease (EMPD). Two patients with EMPD were treated with PDT using 5‐aminolevulinic acid (ALA). Histologically, in both cases, Paget's cells were present within the epidermis. Case 1 was a 92‐year‐old male who underwent total extirpation for treatment of EMPD. Two topical ALA‐PDT treatments were applied to parts of the lesions at a total dose of 200 J/cm2. Case 2 was a 73‐year‐old female, whose lesions in the right labia majora were treated with 3 topical ALA‐PDT sessions at a total dose of 300 J/cm2. Clinical findings after the irradiation showed improvement in both patients, and elimination of tumor cells in the epidermis was confirmed histologically. Case 1 had no recurrence in the irradiation field at three months after PDT. Case 2 had a recurrence only in the periphery parts of the lesions at two months after PDT, but the periphery lesions remitted with two more PDT treatments. Topical ALA‐PDT is an effective treatment for EMPD with tumor cells within the epidermis. It is noninvasive and achieves a cosmetically excellent outcome, especially in elderly patients and those in poor general condition.