[E-cadherin expression patterns of precancerous lesions of the larynx classified according to Ljubljana and WHO classification].

OBJECTIVES To determine if there are differences in the expressions of the E-cadherin adhesion molecule of precancerous laryngeal lesions classified according to Ljubljana and World Health Organization (WHO) classification. PATIENTS AND METHODS We examined 41 cases (3 females, 38 males; mean age 54 years; range 8 to 80 years) of laryngeal hyperplastic-dysplastic lesions from the Kocaeli University Pathology Department archives between 1998-2005. Forty-one laryngeal hyperplastic-dysplastic lesions were classified according to Ljubljana and WHO classification. The cases were classified as pertaining to either low or high risk groups. Sections were stained according to the E-cadherin immunohistochemical method. The relations between risk groups in two different classification systems and E-cadherin expression frequency were detected by Chi-square test. RESULTS According to the WHO classification, the loss of expression detected 32.1% (9/28) in high-risk epithelium and 15.4% (2/13) in low-risk epithelium (p=0.26). According to the Ljubljana classification, the loss of expression detected 38.1% (8/21) in high-risk epithelium and 15% (3/20) in low-risk epithelium (p=0.09). CONCLUSION E-cadherin expression is down regulated with histologic progression in the precancerous lesions of the larynx. However, the presence of normal expression in some carcinoma insitu cases limited their diagnostic value. The presence of normal E-cadherin expression in laryngeal squamous cell carcinoma support this opinion. The Ljubljana system is more accurate for predicting the E-cadherin expression's decrease, or in other words, for demonstrating its malignant potential.