title: Tenascin-C expression in Merkel cell carcinoma lymph node metastasis.
abstract: Expression of tenascin-C (Tn-C) has been shown to correlate with invasion and metastasis in Merkel cell carcinoma (MCC). Cytokeratin-20 (CK-20) is used in differential diagnostics of the primary tumour. The aim of this study was to demonstrate the expression of Tn-C in MCC lymph node metastases. Immunohistochemical staining was performed for five metastatic lymph nodes using a monoclonal antibody against Tn-C and CK-20. All five metastatic lymph nodes expressed Tn-C. The expression concentrated around the vascular structures, invasion borders and fibrotic septae. One of the metastatic lymph nodes was strongly positive for CK-20 while the others showed a focal or negative pattern. The normal lymphoid tissue was negative for Tn-C. Tn-C detected metastatic MCC tissue within the lymph nodes undisputedly. There was a clear distinction between the metastatic and normal lymphatic tissue. Furthermore, invasion to the surrounding tissue was easily demonstrated. Contrary to previous studies, CK-20 expression seemed to fluctuate.
authors.affiliation: Department of Plastic Surgery, Helsinki University Hospital, Finland. virve.koljonen@hus.fi
authors.forename: Virve
authors.initials: V
authors.lastname: Koljonen
authors.forename: Tom
authors.initials: T
authors.lastname: Böhling
authors.forename: Erkki
authors.initials: E
authors.lastname: Tukiainen
authors.forename: Caj
authors.initials: C
authors.lastname: Haglund
authors.forename: Tiina
authors.initials: T
authors.lastname: Jahkola
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D015266:Carcinoma, Merkel Cell / Q000378:metabolism* / Q000556:secondary*; D006801:Humans; D007150:Immunohistochemistry; D053554:Keratin-20; D007633:Keratins / Q000032:analysis; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology*; D019063:Tenascin / Q000032:analysis / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C507499:KRT20 protein, human; D053554:Keratin-20; D019063:Tenascin; D007633:Keratins