CDH1 and sarcomatoid carcinoma: E-cadherin expression was strong and membranous in well and moderately differentiated OSCC and broad invasive fronts, whereas the staining was less intense with both membranous and cytoplasmic localization in poorly differentiated OSCC, and weak or negative in sarcomatoid carcinomas, as well as in invasive fronts showing finger-like and individual tumor cell proliferation.