Is season important for the diagnosis of cutaneous melanoma in southern Brazil? A 10-year hospital-based study.

Background: Exposure to sunlight is an important etiologic factor in cutaneous melanoma (CM). In several countries, more cases of CM are diagnosed in summer than in winter.

Aim: To analyze whether there is seasonal variation in the diagnosis of CM in southern Brazil.

Dermatoscopy of pigmented melanocytic nevi in patients with oculocutaneous albinism.

Oculocutaneous albinism is a group of rare inherited disorders of pigmentation. Some albinos may have a certain degree of melanin production and, consequently, may develop pigmented lesions during their lives. Albinos are also at great risk for developing cutaneous malignancy, including melanomas.

Immunohistochemical expression of matrix metalloproteinase-2 and -9 in melanocytic nevi is altered by ultraviolet B.

Background: Ultraviolet B (UVB) radiation can cause morphological and biological alterations similar to those of melanoma in situ in irradiated melanocytic nevi. matrix metalloproteinase (MMP-2) and -9 appear to be involved with tumour invasion, the formation of metastases and neoangiogenesis in melanomas. The effects of UVB on the immunohistochemical expression of gelatinases in different cell types in melanocytic nevi have not been completely studied.