CK7, CK20, SOX10 and CDX2: expressions and diagnostic values in primary adenocarcinoma of the sinonasal tract

Abstract

To explore the expressions of the cytokeratin 7 (CK7), cytokeratin 20 (CK20), SOX10 and cadual type homeobox transcription factor 2 (CDX2) in primary adenocarcinoma of the sinonasal tract, and evaluate their diagnostic values. A total of 41 paraffin-embeded specimens of primary adenocarcinoma of the sinonasal tract treated in Beijing Tongren Hospital of Capital Medical University were selected from May 2002 to January 2015. All cases were confirmed by histology and clinical data, including 12 cases of non-intestinal sinonasal adenocarcinomas (non-ITACs), 10 cases of intestinal sinonasal adenocarcinomas (ITACs) and 19 cases of salivary gland-type adenocarcinomas (including 12 cases of adenoid cystic carcinomas, 3 cases of polymorphous low grade adenocarcinomas, 2 cases of mucinous adenocarcinomas and 2 cases of acinar cell carcinomas). Expressions of CK7, CK20, SOX10 and CDX2 were assessed by immunohistochemistry staining method. Nuclear staining for CDX2 was identified in all the ITACs,including diffuse nuclear staining in 8 cases and partial nuclear staining in 2 cases. Cytoplasmic staining for CK20 was identified in 9 cases of ITACs, and partial cytoplasmic staining was found in 1 case of non-ITACs, while CK20 was negative in all other adenocarcinomas.Seven cases of ITACs were negative for CK7, while CK7 was positive in all other adenocarcinomas. CK7, but not CDX2 and CK20, was expressed in normal sinonasal epithelium. SOX10 was negative in 10 cases of ITACs and 2 cases of non-ITACs, and positive in all other adenocarcinomas. The sensitivity of CK7-, CK20+, SOX10- and CDX2+ in primary ITACs of the sinonasal tract were 70.0%, 90.0%, 100%, 100%, respectively, and the specificity were 100%, 96.8%, 93.5%, 100%, respectively. Expressions of CK7-, CK20+, SOX10- and CDX2+ have high sensitivity and specificity in ITACs and can be used as a reliable diagnostic marker for primary intestinal-type adenocarcinoma of the sinonasal tract. Additionally, diagnostic value of CDX2 in primary intestinal-type adenocarcinoma of the sinonasal tract is superior to CK20, CK7 and SOX10.