title: Immunohistochemistry of pigmented actinic keratoses, actinic keratoses, melanomas in situ and solar lentigines with Melan-A.
abstract: Distinguishing lentigo maligna from solar lentigo, and pigmented actinic keratosis can sometimes be problematic. Melan-A is an immunohistochemical marker which that can be helpful in decorating the melanocytes of pigmented lesions. A recent report has suggested that Melan-A may spuriously label nests of junctional keratinocytes, potentially leading to the misdiagnosis of melanoma in situ. We compared Melan-A immunohistochemical staining in pigmented actinic keratosis , non-pigmented actinic keratoses , melanoma in situ of lentigo maligna type and solar lentigines. We found a statistically significant increase of Melan-A staining in melanoma in situ, but no statistical difference in the number of junctional Melan-A positively staining cells, in solar lentigines, pigmented actinic keratoses, and non-pigmented actinic keratoses, respectively. In the non non-melanoma samples, the Melan-A A-positive cells located at the dermal-epidermal junction were interspersed and not observed in clusters. Increased staining with Melan-A, in an actinic keratosis, or solar lentigo should raise the possibility of a contiguous melanoma in situ.
authors.affiliation: Department of Dermatology and Pathology, Hershey Medical Center, Hershey, PA 17033, USA. khelm@psu.edu
authors.forename: Klaus
authors.initials: K
authors.lastname: Helm
authors.forename: Jennifer
authors.initials: J
authors.lastname: Findeis-Hosey
mesh_terms: D000368:Aged; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000032:analysis; D006801:Humans; D018327:Hutchinson's Melanotic Freckle / Q000175:diagnosis* / Q000378:metabolism; D007150:Immunohistochemistry; D055623:Keratosis, Actinic / Q000175:diagnosis* / Q000378:metabolism; D007911:Lentigo / Q000175:diagnosis* / Q000378:metabolism; D058965:MART-1 Antigen; D008545:Melanoma / Q000175:diagnosis* / Q000378:metabolism; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins