The presence of Merkel cells and CD10- and CD34-positive stromal cells compared in benign and malignant oral tumors.

BACKGROUND: To describe sequential changes in Merkel cells (MC), and CD10(+) and CD34(+) stromal cells (SC) during the transition from benign to malignant oral lesions and correlate with clinicopathologic parameters.
MATERIALS AND METHODS: Changes in cytokeratin 20-positive (CK20(+)) Merkel cells, CD10(+) and CD34(+) SC were immunohistochemically examined in specimens of 28 oral verrucous carcinomas (VC), 32 squamous cell carcinomas (SCC) and 36 benign squamous lesions (BSL). Immunoreactivity and localized inflammation were measured quantitatively and/or semiquantitatively, and between-group results were statistically compared.
RESULTS: The mean number of CD34(+) SC was significantly lower in VC (57.36) and SCC (33.81) than BSL (351.56, P < 0.001). However, the three tumor types had similar staining level and number of CD10(+) SC. We found a significant difference in the density of MC between BSL and VC (P < 0.001) or SCC (P < 0.001). The number of CK20(+) MC was significantly lower in highly inflamed specimens than mildly inflamed specimens (P = 0.001).
CONCLUSION: CD34(+) SC and to a lesser extent MC, but not CD10(+) SC, reveal statistically different density during the transition from benign to malignant oral lesions. The correlations between the CD34(+) SC expression and squamous lesions may be associated with epithelial dysplasia and/or tumor invasion.