mart-1-antigen and Skin-Diseases

Benign lichenoid keratosis (BLK) is a cutaneous lesion that can clinically mimic malignancy and may represent regression of a pre-existing lesion. BLK may show epidermal pseudo-nests prompting evaluation for a melanocytic lesion. False positivity of MART-1/Melan-A immunostaining in pseudonests has been showed; however, the value of SRY-related HMG-box 10 (SOX10) staining in BLK with features suspicious for a melanocytic proliferation has not been previously reported.. Twenty-one cases of BLK from 2015 to 2020 were identified. Slides were reviewed and SOX10 immunohistochemistry was performed on each case. Subsequently, Melan-A immunohistochemical staining was performed on all cases.. In 10 cases (47.6%), unexpected SOX10 staining was seen in rare to numerous small, single cells in the epidermis above the basal cell layer. No malignancy was identified. Of the 10 cases, 8 (80%) showed suprabasal SOX10 staining did not show similar suprabasal Melan-A staining; 2 (20%) cases showed scattered suprabasal cells positive for Melan-A.. SOX10 immunostaining in BLK can highlight scattered cells in the epidermis (not easily noticeable on routine stain). Performing SOX10 immunostain alone on BLK can prompt a misdiagnosis of a melanocytic lesion and should be done with caution.

Topics: Acanthoma; Biomarkers, Tumor; Humans; Keratosis, Actinic; MART-1 Antigen; Melanocytes; Skin Diseases; Skin Neoplasms; SOXE Transcription Factors

MART-1 is a good candidate antigen for immunotherapy against HLA-A2 patients with melanoma, since it is a highly immunogenic antigen recognized by HLA-A2 and HLA-B45 restricted CD8+ cytotoxic T cells and expressed in the majority of melanoma lesions. In the present study the expression of MART-1 and HLA-A2 on melanocytic cells and CD8+ T cell infiltration was immunohistochemically analyzed. MART-1 was expressed in most melanocytic lesions, while HLA-A2 was down-regulated with melanoma disease progression. Furthermore, concomitant down-regulation of MART-1 and HLA-A2 in melanoma cells was correlated with poor prognosis. These findings suggest both MART-1 and HLA-A2 expression in melanoma lesions should be analyzed for selection of patients eligible for MART-1 based immunotherapy and monitoring for emergence of melanoma cells resistant to T cell therapy.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, Neoplasm; CD8-Positive T-Lymphocytes; Child; Female; Histocompatibility Antigens Class I; HLA-A2 Antigen; Humans; Immunohistochemistry; Lymphocytes, Tumor-Infiltrating; Male; MART-1 Antigen; Melanocytes; Melanoma; Middle Aged; Neoplasm Proteins; Skin Diseases; Skin Neoplasms; Staining and Labeling