Localization of intercellular adhesion molecule-1 in middle ear cholesteatoma

Intercellular adhesion molecule-1 (ICAM-1) may have a role in acquired cholesteatoma, which is usually associated with an inflammatory reaction occurring in the middle ear cavity. The presence of ICAM-1 in human cholesteatomas was demonstrated by an immunoblotting assay using a specific monoclonal anti-ICAM-1 antibody after protein extraction. Distribution of ICAM-1 in the cholesteatoma tissues was then studied by avidin-biotin-peroxidase complex staining. ICAM-1 appeared to be localized on keratinocytes in all layers of the epithelium and on Langerhans cells in both the epithelium and granulation tissue of cholesteatoma. ICAM-1 was not found in the epidermis of normal external ear canal skin, normal tympanic membrane or normal facial skin, but significant staining was seen on keratinocytes of hair follicles and glands in the facial skin. The present study is the first to demonstrate ICAM-1 in cholesteatoma and suggests that it may have an important role in the clinical development of cholesteatoma, including migration, adhesion and proliferation of lymphocytes, Langerhans cells and keratinocytes.