Photodynamic therapy of vulvar intraepithelial neoplasia using methyl aminolevulinate

Sir, Vulvar intraepithelial neoplasia is a pre-cancerous lesion that defines the grade of dysplasia of the vulvar squamous epithelium. According to the classification of the International Society for the Study of Vulva Diseases (ISSVD) 2004, the lesions may be low grade (VIN1) or high grade (VIN2 and VIN3) (1). Currently, there is little consensus regarding the optimal treatment method. Instead of vulvectomy, the tendency is to use more conservative forms of treatment such as laser ablation or local excision. Laser ablation is one of the most generally indicated methods, especially in young women with multicentric disease, in view of its good cosmetic and functional results. Various topical medical treatments including imiquimod, 5FU, dinitrochlorobenzene, bleomycin or interferon-a have also been tried, but they are sometimes very painful and have only limited success (2). No therapy is entirely satisfactory in all cases and the treatment chosen depends on the patient’s age and the site and extent of the lesions, together with the biopsy results. There are studies that have demonstrated the efficacy of photodynamic therapy (PDT) to treat VIN with 5-aminolevulinic acid (ALA). We present a case of VIN type III in an HIV-positive patient successfully treated with PDT and methyl aminolevulinate (MAL). A 38-year-old woman was referred for evaluation of vulvar lesions resistant to laser treatment. Her medical history included: ex-parenteral drug use, smoking 25 packet/year, chronic hepatitis C, hepatitis B viral infection, HIV infection with undetectable viral load and CD4 > 700, and urinary stress incontinence. The patient was undergoing treatment with lamivudin, nevirapin and tenofovir. Ten months previously she had been diagnosed as having grade III vulvar intraepithelial neoplasia and was treated by laser vaporization by the gynaecology service. Six months later, biopsies were performed again and the findings were reported as VIN II with koilocytotic changes suggesting viral infection (pathology not available for review). Because of the persistence of the lesions the patient was referred to the dermatology service. On physical examination, desquamative, pruriginous, erythematous plaques were seen involving the right labia majora, the root of the clitoris and perianal zone (Figure 1). In view of the lack of response to treatment, it was decided to use PDT. Topical MAL was applied to cutaneous and mucosal lesions. The area was then covered with an occlusive adhesive dressing. After 3 h of occlusion, any excess cream was removed using a 0.9% saline solution and the fluorescence of the lesions were evaluated using an ultraviolet lamp. To reduce discomfort, a spinal anesthesia was performed prior to the illumination. The area was exposed with 37 J/cm of red light from a lightemitting diode (LED) source (Aktilite CL128) for 10 minutes. Three months after the first session an improvement was seen, although clinically the lesions persisted. Since the first session was well tolerated it was decided to repeat the treatment. After the second session, the lesions disappeared completely and no signs of dysplasia were found in the biopsies repeated