MYB, CD117 and SOX-10 expression in cutaneous adnexal tumors.

BACKGROUND: Elevated MYB expression has been documented in adenoid cystic carcinoma (ACC), cylindroma, and spiradenoma, but the specificity of this finding is unknown. CD117 and SOX-10 expression also occurs in some cutaneous adnexal tumors. This study assesses MYB, CD117 and SOX-10 expression in cutaneous adnexal tumors. METHODS: Retrospective analysis of 184 benign adnexal tumors (140 eccrine/apocrine, 40 follicular and 10 sebaceous), and 30 malignant adnexal tumors was performed with MYB, SOX-10 and CD117 immunostaining. RESULTS: In the benign adnexal tumors, 16% (23/140) significantly expressed MYB. MYB expression was limited to cylindromas and to a lesser extent, spiradenomas in the benign cohort. Elevated MYB expression was detected in mucinous carcinoma, endocrine mucin-producing sweat gland carcinoma and 1 and 4 cases of extramammary Paget's disease (EMPD) in the malignant cohort. CD117 and SOX-10 had similar overall positivity rates in benign apocrine and eccrine tumors (45% and 68% respectively), and were generally negative in other benign and malignant adnexal tumors. CONCLUSION: Expression of MYB appears limited to a small number of cutaneous adnexal tumors, including cylindromas, spiradenomas, ACCs, mucinous carcinoma, endocrine mucin-producing sweat gland carcinoma and some cases of EMPD.

Comparative analysis of cytokeratin 15, TDAG51, cytokeratin 20 and androgen receptor in sclerosing adnexal neoplasms and variants of basal cell carcinoma.

BACKGROUND: Desmoplastic trichoepithelioma (DTE), morpheaform basal cell carcinoma (BCC) and microcystic adnexal carcinoma (MAC) are sclerosing adnexal neoplasms with overlapping histopathologic features. We compared cytokeratin 15, (CK15), T-cell death-associated gene 51 (TDAG51), cytokeratin 20 (CK20) and androgen receptor (AR) in differentiating these tumors and assessed their expression in BCC subtypes. METHODS: Fifteen DTE, 15 infundibulocystic BCC, 18 micronodular BCC, 18 morpheaform BCC and 6 MAC were assessed for CK15, TDAG51, CK20 and AR expression. RESULTS: Quantitative CK15 staining was higher in DTE compared with BCC (p < 0.0001) and MAC (p = 0.02). Quantitative TDAG51 staining was higher in DTE than BCC (p < 0.0001). The CK20+AR- immunophenotype was 100% sensitive and specific in diagnosing DTE. The CK20-AR+ immunophenotype was 95.24% specific and 83.33% sensitive for BCC. The CK20-AR- immunophenotype was 83.33% sensitive and 90.91% specific for MAC. CK15, CK20 and AR were positive in 87, 53 and 67% of infundibulocystic BCC cases, respectively. CONCLUSION: Combination of CK20 and AR best differentiated these sclerosing adnexal neoplasms. Greater positivity for CK15 and TDAG51 generally favors benign lesions. Infundibulocystic BCC has higher CK20 and lower AR immunopositivity than other BCC variants and a high degree of CK15 and TDAG51 positivity.