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  • Immunohistochemistry of pigmented actinic keratoses, actinic keratoses, melanomas in situ and solar lentigines with Melan-A.

Immunohistochemistry of pigmented actinic keratoses, actinic keratoses, melanomas in situ and solar lentigines with Melan-A.

Journal of cutaneous pathology (2008-05-23)
Klaus Helm, Jennifer Findeis-Hosey
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.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
MART-1 (Melan A) (A103) Mouse Monoclonal Antibody