Since the E-cadherin-catenin complex is of importance in the cancerogenesis of epithelial tumors, we examined the expression of E-cadherin and beta-catenin in sebaceous adenocarcinomas of the eyelid and correlated the results with clinicopathological parameters. The study included histological specimen of 32 patients with sebaceous adenocarcinomas of the eyelid. The expression of E-cadherin, beta-catenin, and Ki-67 nuclear antigen was analyzed by immunohistochemistry. The membranous expression of E-cadherin and of beta-catenin was reduced in 17 (53%) patients and 18 (56%) patients, respectively, while elevated cytoplasmic levels and a nuclear accumulation of beta-catenin were found in 27 (84%) and six (19%) patients, respectively. The low expression of membranous beta-catenin was associated with a high degree of tumor infiltration (p = 0.02), high amount of inflammation (p = 0.01), and high degree of poor tumor differentiation (p < 0.001). In a similar manner, a low membranous E-cadherin expression in tumors was significantly associated with poor tumor differentiation (p = 0.001) and high tumor cell proliferation rate (p = 0.004). The Ki-67 proliferation index was significantly higher in the group with low membranous E-cadherin expression than in the group with high membranous E-cadherin expression (62.3 +/- 20.8 versus 42.1 +/- 15.3; p = 0.004). The membranous E-cadherin expression and the membranous beta-catenin expression were significantly associated with each other (Fisher's exact probability test, p = 0.03). Sebaceous eyelid adenocarcinomas showed a decrease in the membranous expression of E-cadherin and of beta-catenin. These changes were associated with poor tumor differentiation and an increase in the tumor infiltration and inflammation, pointing at a potential role of a low E-cadherin and low beta-catenin expression for poor prognosis of sebaceous eyelid adenocarcinomas. Correspondingly, the cell proliferation index and the expression of E-cadherin were inversely correlated with each other. The findings suggest that the immunohistochemical detection of a low E-cadherin and low beta-catenin expression may help in the examination and staging of sebaceous eyelid adenocarcinomas.