Treatment of lentigo maligna

Abstract

Lentigo maligna (LM) is the in situ phase of lentigo maligna melanoma (LMM) and, if left untreated, 30-50% of cases will progress to LMM, which is now thought to behave as aggressively as any other melanoma. Literature on the of treatment of LM including conventional surgery, micrographic Mohs surgery, cryosurgery, radiotherapy, electrodesiccation and curettage. 5-fluorouracil (5-FU), azelaic acid, retinoic acid and lasers are reviewed. It is concluded that micrographic Mohs surgery has the lowest recurrence rates and that conventional surgery, cryosurgery and radiotherapy all have recurrence rates in the order of 7-10%. Therefore, on the basis of the current literature available, all three of these methods could be recommended as primary treatment of LM. It is extremely important when choosing one of the above treatments that the physician is adequately trained in the appropriate technique and understands the limitation of the method used and the need for close follow up of the patient.

Prolonged evolution of a lentigo maligna

“…19,21,22 This problem, as well as the importance of conserving tissue in cosmetically important areas where LMs are often located, has led to the recent practice of using Mohs surgery to treat some of these lesions. 13 Two studies that have looked at the local recurrence rates of LM in patients undergoing Mohs surgery have shown recurrence rates of 0% and 6%. 22,23 One of the limitations of using Mohs surgery to treat LMs includes the challenge of accurately interpreting premalignant melanocytes in frozen sections.…”

“…12 Destructive therapies are sometimes used to treat LM, particularly in elderly patients. 13 Reported local recurrence rates after such treatments can vary widely. For example, studies looking at LMs treated with cryotherapy show recurrence rates in the range of 0% to 50%.…”

“…For example, studies looking at LMs treated with cryotherapy show recurrence rates in the range of 0% to 50%. 13 One of the main disadvantages of destructive modalities such as cryotherapy, electrodesiccation and curettage, superficial radiotherapy, topical 5-fluorouracil, etc, is that these preclude histologic evaluation to rule out LMM. 2 There is also a tendency for these therapies to spare deep adnexal melanocytes with recurrences resulting from their regrowth, 2,13,14 as well as a failure to recognize and destroy atypical melanocytes that may extend beyond the clinical margins.…”

Mohs micrographic surgery in the treatment of lentigo maligna and melanoma

“…Destructive methods are those which destroy the tumor in situ, and as a consequence do not provide a specimen for subsequent analysis by the pathologist. These methods carry recurrence rates of 3-14% [2,3] for radiotherapy, 7-10% for cryosurgery [4], 22% for azelaic acid, 27% for electrodessication and curettage, and 100% for 5-fluorouracil [5]. High recurrence rates are likely related to inadequate treatment of deep periadnexal tumor cells, or those beyond the clinical margin of the lesion.…”

Treatment of Cutaneous Melanoma of the Face by Mohs Micrographic Surgery

“…3 The treatment of LM and LMM has included conventional surgery as well as the destructive modalities of cryotherapy and radiotherapy. [4][5][6][7] Incomplete removal/destruction because of unrecognized, subclinical extension of melanoma cells can result in lesion recurrence. Previous studies have identified the margins of LM by sequential removal of levels of tissue around lesions using fixed histopathologic specimens and HMB-45 monoclonal antibody staining.…”