Melanoma in situ of lentigo maligna type in a young woman

Melanocyte Density in the Diagnosis of Melanoma In Situ in Sun-Damaged Skin

ABSTRACT

Histologic differentiation between melanoma in situ in chronically sun-damaged skin (CSDS) [lentigo maligna (LM)] and CSDS without malignancy is difficult because signs of melanocyte activation and proliferation are found in both. A potentially reliable and quantifiable criterion is melanocyte density (MD). Here, we evaluated whether and to what extent MD allows the distinction between LM and CSDS, which is particularly relevant for the evaluation of borderline cases and surgical margins.Articles assessing MD in LM and/or CSDS were evaluated in a systematic review. The results were categorized and compared according to staining. Cutoff values were included whenever stated.Twenty articles matched the selection criteria. Six hundred forty-four samples of CSDS and 227 samples of LM were considered. In each individual study, mean MD scores were higher for LM than for CSDS. However, looking at the overall study situation, it becomes clear that the data are very heterogeneous and show overlaps. Therefore, no reliable orientation value can be derived. Only 1 article defined a cutoff value.The data of MD in LM in contrast to CSDS were sparse, and a defined cutoff value was only mentioned in 1 article for microphthalmia-associated transcription factor, which cannot yet be generalized. Especially regarding the importance for the definition of surgical resection margins, this unsatisfactory data set highlights the need for further studies. More precise diagnostic criteria could spare some patients extensive and possibly disfiguring surgery.

Mohs surgery for the treatment of lentigo maligna and lentigo maligna melanoma - a systematic review

BACKGROUND

The role of Mohs micrographic surgery (MMS) in the treatment of lentigo maligna (LM), and lentigo maligna melanoma (LMM) has been controversial. The use of frozen sections is commonly cited as a suboptimal way to distinguish atypical melanocytes, resulting in traditional wide-local excision techniques as the mainstay of therapy.

OBJECTIVE

To compare the success of MMS as a treatment option for LM and LMM with that of traditional surgical and nonsurgical therapies by analyzing the published recurrence rates of these lesions after MMS procedures.

METHODS AND MATERIALS

PubMed database was used to find relevant articles with search terms related to MMS, LM, and LMM.

RESULTS

The search strategy resulted in 27 articles that fulfilled the inclusion criteria. All studies considered; MMS provided a 1.35% recurrence rate with follow-up times ranging from 1 month to 5 years. Specifically, studies employing classical MMS and MMS with rush sections provided recurrence rates of 1.17% and 2.4%, respectively.

CONCLUSION

MMS is one of the most successful treatment options for LM and LMM, with published evidence of improved recurrence rates when compared to other forms of therapy. Additional clinical trials are needed to further delineate the role of MMS in the treatment algorithm for these conditions.