Mast cells and dendritic cells in basal cell carcinoma stroma

BACKGROUND. The interaction of tumors with the surrounding stroma has become an important topic in tumor biology. Basal cell carcinoma (BCC) stroma has been characterized as hypervascular and rich in mast cells. The presence of dermal dendrocytes thought to have both antigen presenting and wound healing functions has recently been reported in BCC stroma. GP1b-alpha is a newly described vascular adhesion molecule with potential significance in tumor biology. OBJECTIVE. TO further characterize the cellular phenotype of BCC stroma. METHODS. Eleven BCCs (8 nodular, 2 sclerosing, 1 adenoid-cystic) were examined using immunohistochemical techniques for the presence of antigens specific to vascular endothelium, mast cells, and dermal dendrocytes. RESULTS. The stroma of all BCCs demonstrated increased vascularity, increased numbers of mast cells, and increased numbers of dermal dendrocytes expressing both CD34 and GP1b-alpha adjacent to tumor nests. No differences: in antigen expression were observed between histologic subtypes of BCC. CONCLUSION. The close proximity of stromal mast cells and dermal dendrocytes surrounding BCC nests suggests a biologically significant interaction. The pattern observed is similar to that observed in healing wounds.