Tenascin expression in intraepithelial neoplasia and invasive carcinoma ofthe uterine cervix

Objective.-To determine whether the expression of the matrix protein tenasc in (TN) is of diagnostic or prognostic value in cervical intraepithelial ne oplasia (CIN). Design.-Tenascin expression was evaluated in 75 formalin-fixed, paraffin-em bedded biopsy and surgical specimens of the uterine cervix. Specimens inclu ded 15 low-grade squamous neoplastic lesions (CIN I), 30 high-grade squamou s neoplastic lesions (CIN II and CIN III), 5 microinvasive carcinomas, and 15 invasive squamous carcinomas. Five normal cervices and 5 examples of cer vicitis were used as controls. Expression of TN was studied by immunohistoc hemistry with a monoclonal mouse anti-human tenascin antibody. Tenascin exp ression in the basement membrane and in the stroma was arbitrarily graded a s normal or slightly, moderately, or markedly increased. Results.-In the normal cervix, TN formed a thin band along the basement mem brane of the squamous epithelium, except for the transformation zone, where the bands splintered and delicate TN fibers were present in the adjacent s troma. In cervicitis, TN bands were splintered in the basement membrane and the protein was weakly expressed in the stroma infiltrated by inflammatory cells. In the 45 CIN lesions, regardless of grade, the TN bands in the bas ement membrane were slightly (25 cases) or moderately (20 cases) increased. In CIN lesions with chronic stromal inflammation, a slight increase in str omal staining was observed, similar to the findings in cervicitis. In micro invasive and frankly invasive squamous cell carcinomas, TN expression was m arkedly increased in the basement membrane and in the stroma surrounding th e invasive nests of cancer cells. Conclusion.-Tenascin expression may be of value in the assessment of early stromal invasion in cancer of the uterine cervix. Tenascin expression is of no value in distinguishing various grades of CIN and, therefore, is not a predictor of future behavior.