Abstract
The diagnosis of lentigo maligna (LM) is often challenging for both clinicians and pathologists. LM is widely regarded as a form of melanoma in situ occurring in severely sun-damaged skin with characteristic clinical and pathologic features. However, compared with other forms of in situ melanoma, it often has a long-term clinical course for evolution to invasive melanoma. Some authorities advocate dividing LM into premalignant/precursor and in situ melanoma (LM in situ melanoma) phases, implying a lesser risk of the former for developing invasive melanoma. However, this subtle morphologic distinction does not necessarily correlate well with clinical outcome. An initial tissue sample for histologic diagnosis is commonly a small proportion of the lesion and may not be representative/diagnostic of LM. New clinical diagnostic tools including dermoscopy and in vivo confocal microscopy have improved the accuracy of both clinical diagnosis of LM and also defining the peripheral extent of the lesion for definitive treatment. In this review, the authors discuss these challenges and controversies in LM and provide recommendations for clinicopathologic diagnosis and management.
Acknowledgements
The authors gratefully acknowledge assistance provided to them by their colleagues at Toronto General Hospital, University of Toronto, Royal Columbian Hospital, Melanoma Institute Australia, Royal Prince Alfred Hospital, and the University of Sydney. They are particularly appreciative of the assistance provided to them by Prof. Stanley W McCarthy AO and Dr Danny Ghazarian over many years, for generously sharing their experience, knowledge and case material. The authors also thank Prof. Jonathan Stretch for kindly providing the image utilized to produce .
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.