Laminin Immunostaining in Biopsies as a Useful Biomarker of Early Invasion in Actinic Cheilitis and Differential Diagnosis Between Actinic Cheilitis and Lip Cancer: New Insights.

BACKGROUND: Squamous cell carcinoma of the lip (LSCC) and oral cavity can be life-threatening if not diagnosed early. Precancerous lesions like actinic cheilitis (AC), can transform into LSCC. Laminin is a fundamental component for basement membrane (BM) and its integrity may prevent neoplastic invasion. Therefore, laminin immunostaining of BM may be useful in identifying early invasion in actinic cheilitis and thus in the differential diagnosis between AC and invasive LSCC or high-grade epithelial dysplasia (ED). MATERIALS AND METHODS: Biopsies from 46 patients with oral lesions were histologically analyzed and immunohistochemically stained for laminin-1. RESULTS: AC was diagnosed in 34 patients and LSCC in 12 patients, including 3 patients with AC and concomitant high-grade ED/in situ carcinoma. Laminin-1 immunostaining revealed intense and linear expression of the BM in AC with low-grade ED. Loss of laminin expression was observed in LSCC. Intracellular laminin expression in parabasal cells was noted in AC with high-grade ED/in situ carcinoma. CONCLUSION: Laminin immunostaining could be useful in identifying AC cases suspected of early invasion. It could also contribute to the histopathological differential diagnosis between AC with low- and high-grade ED and between AC and invasive LSCC. The findings of this study provide new insights into the mechanism involved in the progression process of AC into LSCC, encouraging preclinical studies that may document the stochastic role of laminin in this process.

Different patterns of p16 immunoreactivity in cervical biopsies: correlation to lesion grade and HPV detection, with a review of the literature.

p16 is one extensively studied marker in gynecological pathology. However, its routine application in the diagnosis of squamous intraepithelial lesions of the uterine cervix may present difficulties for the general pathologist. The aim of the present study was to examine a series of 100 cervical biopsies/LEEP specimens, with detailed HPV-typing, for patterns of p16 immunoreactivity and possible correlations with morphology and HPV types. Four patterns of immunopositivity were recognized, according to the distribution of positively stained cells, and these correlated to lesion grade. A review of the pertinent literature concerning p16 immunoreactivity in squamous intraepithelial lesions and nonneoplastic epithelia of the uterine cervix is included in an effort to summarize the existing data and the remaining questions at both the practical and theoretical level.