Evaluation of sensitivity of invers approach in dermoscopic differential diagnosis of lentigo maligna

Introduction: Lentigo maligna is a subtype of malignant melanoma that occurs in chronically sun-exposed skin areas such as the head and neck region. It may be overlooked until the late stages of its progression, especially because of the other signs of sun damage on the skin and its slow growth rate. Therefore, dermoscopic evaluation algorithms are needed to increase diagnostic sensitivity and specificity. Aim: The aim of this study is to prospectively determine the sensitivity of the newly defined inverse approach in the dermoscopic differential diagnosis of lentigo maligna and evaluate its applicability in dermatology practice. Methods: A total of 68 patients with hyperpigmented macules in the head and neck region were included in the study group, and 947 lesions were examined clinically and dermoscopically. The data were analyzed using the Statistical Package for the Social Sciences (SPSS) version 26.0 for Windows. Results: Out of a total of 947 lesions evaluated in the study, 940 were evaluated dermoscopically as benign. According to the inverse approach, 6 of the 7 lesions were histopathologically diagnosed as lentigo maligna and 1 was diagnosed as atypical lentiginous proliferation. 2 of 6 lentigo maligna were not diagnosed according to classical dermoscopic criteria. The sensitivity of the method was found to be 100% and spesifity of the method was found to be %99,8. Conclusion: According to the results of our study, the inverse approach is an easily applicable diagnostic algorithm in the diagnosis of lentigo maligna with high sensitivity and spesifity. It should be used as an additional algorithm in dermoscopic examinations of patients with chronic sun damage and presenting with multiple hyperpigmented macules in the head and neck region.