CD44 is an adhesion molecule, which binds hyaluronic acid and participates in a number of cell-cell interactions, including lymphocyte homing. The CD44 antigen is expressed on approximately 90% of lymphocytes, monocytes, granulocytes, and, in lower amounts on thymocytes, fibroblasts, and erythrocytes. Platelets lack CD44. In non-haematopoietic tissues, CD44 is widely distributed. The secretory component is isolated from human colostrum and is of help in more precise grading of endometrial carcinoma. In this study we examined CD44 and secretory component expression in adenomatous hyperplasia, atypical adenomatous hyperplasia and well-differentiated adenocarcinoma (cribriform pattern). The results showed decreased expression of CD44 and increased expression of secretory component as the lesion progressed to malignancy.