ABSTRACT
<p><b>OBJECTIVE</b>To study the expression of neutral endopeptidase (CD10) and motility-related protein-1 (CD9) in malignant melanoma and their clinical significance.</p><p><b>METHODS</b>Immunohistochemical study for CD10 and CD9 using Streptavidin-biotin complex technique was carried out in 48 cases of primary cutaneous malignant melanoma (CMM), 23 cases of metastatic melanoma and 23 cases of benign nevus.</p><p><b>RESULTS</b>The positivity rate of CD10 was highest in metastatic melanoma and lowest in benign nevus (P < 0.01). In contrast, the positivity rate of CD9 in metastatic melanoma was lower than that in CMM (P < 0.05). The expression of CD9 was inversely correlated with that of CD10 in malignant melanoma (CMM: r = -0.40, P = 0.005; metastatic MM: r = -0.44, P = 0.034). The expression of CD10 and CD9 in CMM also correlated with tumor histology, Clark's level of invasion and presence of nodal metastasis. A similar relationship was also observed for CD10 and CD9 expression in stromal fibroblasts of CMM (r = -0.43, P = 0.007).</p><p><b>CONCLUSIONS</b>CD10 and CD9 expression correlates with the invasiveness and metastatic potential of malignant melanoma; both factors may demonstrate a counteracting effect. These two markers have potential implications in prognostic assessment of CMM. Stromal fibroblasts may also play an important role in the progression of CMM.</p>