Halo nevi, known as leukoderma acquisitum centrifugum, Sutton nevus, leukopigmentary nevus, perinevoid vitiligo, or perinevoid leukoderma, together with vitiligo and melanoma-associated hypopigmentation, belong to the group of dermatoses designated as immunological leukodermas. The etiology and pathogenesis of halo nevi has not been fully elucidated. There are several mechanisms through which a lymphocytic infiltrate can induce tumoral regression. In this review, we aimed to update the knowledge about Sutton nevi starting with the clinical appearance and dermoscopic features, continuing with information regarding conventional microscopy, immunohistochemistry, and the immunological mechanisms responsible for the occurrence of halo nevi. We also included in the article original unpublished results when discussing dermoscopic, pathologic and immunohistochemical results in halo nevi. Sutton nevi are valuable models for studying antitumor reactions that the human body can generate. The slow and effective mechanism against a melanocytic skin tumor can teach us important lessons about both autoimmune diseases and anticancer defenses.

Cutaneous melanoma is the most aggressive form of skin cancer and its incidence is unfortunately increasing. In the last decades, a progressive increase of new cases of diagnosed thin melanoma has been noted. This may be due to earlier detection, better surveillance, improved diagnostic criteria or increased exposure to sunlight. Despite the fact that Breslow tumor thickness has the strongest proven prognostic significance, there are still thin melanomas that metastasize and thick melanomas with favorable evolution. Therefore, the identification of strong predictive factors for survival is mandatory, particularly for patients with thin melanoma.

Non-melanoma skin cancer (NMSC) is the most common type of neoplasm affecting Caucasian individuals, with squamous-cell carcinoma (cSCC) being the second most common type of NMSC after basal-cell carcinoma. The immunohistochemical study of cSCC is of particular importance, especially for the diagnosis of its rare forms, for which accurate and early diagnosis is crucial for survival. In the present review of the literature, the potentially significant value of immunohistochemical markers were highlighted to more accurately assess the biological behaviour, the prognosis of cSCC and to optimize case management. The immunohistochemical markers were classified from a pathophysiological point of view in order to present the mechanism by which carcinogenesis occurs with its subsequent evolution and therefore, to develop a more accurate novel risk staging criteria for this type of neoplasm.