Lentigo maligna (LM) is an in-situ form of melanoma which occurs on sun-exposed skin. Untreated LM can progress into invasive lentigo maligna melanoma (LMM). The incidence of LM/LMM is constantly increasing as the population grows older and lifelong sun-exposure is on the rise. Clinically it is difficult both to determine the borderline of LM as well as to differentiate LMM from LM. A novel imaging method hyperspectral imaging system (HIS) can be used for delineating margins of LM and for spotting invasion inside LM lesion. The gold standard treatment for LM is surgical excision with adequate (≥5 mm) margins. Due to large size of LM lesions and typical location on face or neck the surgical treatment is challenging and can cause aesthetic and functional deficit for the patient. Furthermore, LM patients tend to be elderly who may have anesthetic contraindications. Other treatment modalities for LM have been studied but none of them still has proved to be efficient enough. Recently, photodynamic treatment (PDT) has been suggested as a promising novel treatment method for LM.