Reflectance confocal microscopy and Lentigo maligna management

Abstract

Lentigo Maligna (LM) is a form of melanoma in situ that can arise from atypical melanocytic intraepidermal proliferation (AIMP). LM may progress to Lentigo Maligna Melanoma (LMM), which is invasive and requires more aggressive treatment. Together, AIMP, LM, and LMM form the Lentigo Maligna Spectrum.

AIMP is controversial—some view it as benign, while others classify it as early melanoma in situ, leading to differing management strategies. Clinical and dermoscopic features often fail to distinguish between AIMP, LM, and LMM. Histopathology remains the gold standard, but sampling bias may hinder accurate diagnosis due to the coexistence of different components in one lesion.

A key challenge is improving diagnostic accuracy to guide appropriate treatment or surveillance. Defining which treatment is suitable for each disease stage remains unclear. Clinical and dermoscopic evaluations alone cannot reliably indicate disease progression or identify the ideal biopsy site.

Reflectance Confocal Microscopy (RCM) offers non-invasive, cellular-level imaging that can detect both visible and subclinical changes. RCM has shown promise in guiding biopsies, improving diagnosis, and monitoring therapeutic response.

This PhD thesis addresses critical knowledge gaps by evaluating RCM’s accuracy in identifying LMM's invasive component and distinguishing early stages like AIMP and LM. It also proposes a Lentigo Maligna Spectrum score based on key RCM features to support clinical decision-making and improve lesion management.