Expression of cell adhesion molecules in chordomas: an immunohistochemical study of 16 cases.

Chordomas are thought to be tumors originating from notochord remnants characterized histologically by cohesive cells with epithelial features and by immunohistochemical expression of epithelial markers. To investigate the expression and distribution of cell adhesion molecules in chordomas, we immunohistochemically studied the expression of representative cell adhesion molecules, E-cadherin, P-cadherin, N-cadherin, beta-catenin, CD44, ICAM-1 (CD54), NCAM (CD56), and VCAM-1 (CD106) in 16 tumors from 16 patients (skull base, n=5; cervical, n=2; sacral, n=9) and 3 cases of fetal notochord. Of 16 tumors, 12 (75.0%) expressed membranous immunoreactivity for NCAM, 10 (62.5%) for VCAM-1, 9 (56.3%) for CD44, 8 (50.0%) for N-cadherin, 6 (37.5%) for beta-catenin, 4 (25%) for ICAM-1, and 1 (6.3%) for P-cadherin. Nuclear staining for E-cadherin was recognized in 11 (68.8%) tumors, and membranous staining for E-cadherin in 3 (18.8%); none of the tumors showed both nuclear and membranous staining. Intranuclear accumulation of beta-catenin was not found in any chordoma. One fetal notochord case showed immunoreactivity for N-cadherin, E-cadherin (some cells showed staining in both cytoplasm and nuclei), CD44 and beta-catenin. These results indicate that chordomas frequently express immunoreactivity for multiple adhesion molecules including VCAM, CD44 and N-cadherin, as well as for NCAM and E-cadherin, as previously reported. These molecules may participate in producing the cellular cohesion evident in tumor morphological structure. Although the precise underlying mechanisms remain to be elucidated, the high frequency of nuclear expression of E-cadherin (11 of 16 cases) may be diagnostically useful.