Lentigo maligna and lentigo maligna melanoma
Lentigo maligna is a macular lesion, most typically on the sun exposed skin of the face. Usually consisting of variable shades of brown, it can be amelanotic. Lentigo maligna expands as a flat patch for many years, sometimes decades.
Eventually, within it an invasive component can develop, lentigo maligna melanoma. Lentigo maligna melanoma is manifested as a thickening within the larger macular area of lentigo maligna. This nodularity is slowly progressive. Metastases can occur from this invasive component.
- The treatment of choice of lentigo maligna and lentigo maligna melanoma is usually surgical excision. Removal of the lentigo maligna prevents development of the invasive component. Such removal must be complete, as atypical melanocytes extend down hair follicles and adnexae.
- Superficial liquid nitrogen cryotherapy does not remove this deeper in situ component.
- Similarly, topical treatment with agents such as azelaic acid may not completely remove the atypical component.
- Radiation therapy is an alternative to surgical excision, particularly if the lesion is very large and surgery would cause significant disfigurement.