1 Abstract and Introduction
Lentigo maligna is a melanocytic neoplasm, often regarded as 'melanoma in situ,' which may progress to lentigo maligna melanoma. Lentigo maligna clinically presents as a pigmented, asymmetric macule that originates on the head and neck and spreads slowly. The preferred method for diagnosing lentigo maligna is excisional biopsy. Histology shows proliferation of atypical melanocytes at the epidermal–dermal junction in small nests or single cells. The differential diagnosis includes solar lentigo, seborrheic keratosis, lichen planus-like keratosis, pigmented actinic keratosis, and melanocytic nevus. Stains used in diagnosis include hematoxylin and eosin, HMB-45, MART-1/Melan-A, Mel-5, and S-100. Surgical excision is the preferred treatment for lentigo maligna. Second-line techniques include medical (topical imiquimod) and destructive therapy.
Lentigo maligna is a pre-malignant melanocytic neoplasm, which originates on chronically sun-exposed skin, particularly the head and neck. Its progression leads to lentigo maligna melanoma, one of the four common subtypes of malignant melanoma. Forms of lentigo maligna that may progress to lentigo maligna melanoma in situ are often termed 'melanoma in situ, lentigo maligna type.' Lentigo maligna typically presents as a pigmented 1–3 mm macule. Although lentigo maligna usually occurs in white males with a peak incidence in the sixth and seventh decades of life, lesions have also been diagnosed in the second and third decades.[1–3] Diagnosis and treatment of lentigo maligna remain complex, as the recurrence rate is quite high (2–50%). In this article, we review the history, clinical presentation, histology, diagnosis, and management of lentigo maligna. The primary database utilized for this article was PubMed. The search terms used included 'lentigo maligna,' 'lentigo maligna melanoma,' and 'melanoma in situ'. These phrases were combined with the following terms: 'diagnosis,' 'pathology,' 'histopathology,' and 'treatment.' On the basis of the results, more specific terms were combined with the above, which included 'digital epiluminescence microscopy,' 'Mohs micrographic surgery,' 'geometric excision,' 'and 'spaghetti technique.'
Am J Clin Dermatol. 2013;14(6):473-480. © 2013 Adis Springer International Publishing AG