Tenascin distribution in basal cell carcinomas.

The distribution of tenascin, an extracellular matrix protein highly expressed in the stroma around sites of epithelial-mesenchymal interaction during morphogenesis and in malignant neoplasms, was assessed in cryostat sections of 17 basal cell carcinomas using a polyclonal antibody. There was marked staining of the vascularized stroma around neoplastic islands, usually as an intense, well-defined band, but being more widespread and diffuse in sclerosing, infiltrative areas. Apparently enhanced staining was seen in tumours showing retraction artefact, which may be related to the observation that tenascin interferes with the cell binding function of fibronectin. Reduced staining was seen in areas showing evidence of tumour regression. Tenascin is an important component of the epithelial-mesenchymal interactive process and further studies on its distribution in benign and malignant skin tumours are required.