Consultations & Comments: Monitoring Lentigo Maligna After Excision

Are follow-up radiographs or laboratory studies needed when lentigo maligna has been completely excised and a biopsy has been performed?

---- MD

Lentigo maligna is a superficial form of melanoma that develops in sun-damaged skin (Figure). With excision, its cure rate is higher than 95%. It is best treated with Mohs micrographic surgery to ensure that it is completely excised.

Up to 25% of lesions identified as lentigo maligna on biopsy show areas of invasion on the excised specimen. Therefore, the specimen must be carefully examined for evidence of invasion--not just for a clear margin. If no invasion is seen and the lentigo maligna has been completely removed, neither laboratory work nor radiographs are indicated. The risk of metastasis is extremely low, and a false-positive result (leading to further testing) is more likely than a true-positive result. However, close follow-up, with complete skin examinations and comprehensive reviews of systems, is needed. If a review of systems raises any concerns, then laboratory testing and radiographs should be obtained.

---- Leslie J. Christenson,

Department of Dermatology

Mayo Clinic

Rochester, Minn