To the Editor.—
Reports have appeared in the lay press and medical literature that suggest pigmented lesions of the skin, particularly lentigo maligna (Hutchinson's melanotic freckle) and dysplastic nevi, may be successfully treated with topical tretinoin (all-transretinoic acid).1-3 Others4 have documented the regression of metastatic melanoma following the topical application of tretinoin. We were prompted to treat lentigo maligna with topical tretinoin after having observed the regression of the epidermal component of an invasive melanoma.5At The Sydney Melanoma Unit (Australia), four patients with biopsy-proved lentigo maligna of the face or upper extremity have recently been treated. After informed consent was obtained from the patients, each of the four lesions was photographed. Patients received specific written instructions in order to facilitate compliance: they were instructed to apply tretinoin 0.05% cream to the lesion twice daily without occlusion and to apply a high SPF sunscreen throughout the daylight hours.
Rivers JK, McCarthy WH. No Effect of Topical Tretinoin on Lentigo Maligna. Arch Dermatol. 1991;127(1):129. doi:10.1001/archderm.1991.01680010141034