Objective: To investigate the expression level of E-cadherin in spinal plasma cell myeloma and its relationship with the clinicopathological indexes of spinal plasma cell myeloma. Methods: The expression of E-cadherin was detected in 41 cases of spinal plasma cell myeloma and 14 cases of simple bone cysts by using S-P （streptavidin-perosidase） immunohistochemical staining. The relationship between E-cadherin expression and the clinicopathologica1 features was analyzed. Results: In spinal plasma cell myelomas

the positive expression rate of E-cadherin （46.34%） was higher than that in simple bone cyst tissues （all negative） （P<0.01）. And the expression of E-cadherin had no obvious relationship with patients’ age

gender

clinical classification or M-component （P>0.05）

but had relationship with the classification of light chain. The expression rate in lambda chain subgroup was lower than that in the others （P<0.05）. We also found the E-cadherin negative patients had a higher overall survival rate than those who had strong E-cadherin expression （P<0.05）. Conclusion: E-cadherin expressed higher in spinal plasma cell myelomas than in simple bone cyst tissues and its expression had relationship with the light chain classification in spinal plasma cell myeloma. The patients with no stain of E-cadherin may have a poor prognosis. Detecting the type of light chain associated with expression of E-cadherin might be helpful in evaluating the outcome of spinal PCM patients.