EXPRESSION OF E-CADHERIN AND N-CADHERIN IN SURFACE EPITHELIAL-STROMALTUMORS OF THE OVARY DISTINGUISHES MUCINOUS FROM SEROUS AND ENDOMETRIOID TUMORS

This study examines the expression of E-cadherin and N-cadherin in the most common epithelial tumors of the ovary. The homotypic interaction s of distinctive members of the cadherin family of cell-cell adhesion molecules segregate cells into tissues during embryonic development, a nd their expression in tumors can be used to trace the histogenesis of tumor cells. Because the surface epithelium of the ovary is a modifie d mesothelium, we speculated that the expression of E (epithelial)-cad herin and N (neural, mesodermal)-cadherin may provide clues about the controversial origin of common epithelial ovarian tumors. Immunohistoc hemistry was performed in paraffin sections using well-characterized m onoclonal antibodies to E and N-cadherin and heat-induced antigen-retr ieval methods. We found that serous and endometrioid tumors express bo th E and N-cadherin. Zn contrast, mucinous tumors strongly express E-c adherin, but no N-cadherin. The presence of N-cadherin in serous and e ndometrioid tumors traces their origin to the mesoderm-derived ovarian surface epithelium. The absence of N-cadherin in mucinous tumors clea rly distinguishes them from the former, suggesting histogenesis from a cell lineage other than the ovarian surface epithelium or aberrant di fferentiation mechanisms associated with neoplastic transformation. Co pyright (C) 1997 by W.B. Saunders Company.