The significance of mast cells associated with basal cell carcinoma.

In the stroma of basal cell carcinoma (BCC), the numbers of mast cells are increased, but their significance remains unknown. In a retrospective histological study of 74 cases, we investigated the significance of mast cells related to BCC and the possible relationship between increased numbers of mast cells and clinical and histological parameters including the patients' age, sex, subtype of BCC, and severity of peritumoral inflammation. We found a significant increase in peritumoral mast cell numbers over those in uninvolved skin (p<0.0001). Morpheaform BCCs had significantly more mast cells than did the other variants (p=0.047). No significant relationship was found between mast cell number and the degree of peritumoral inflammation, patient age, or gender. Our results support previous reports indicating that mast cell numbers are increased in RCC, particularly in its morphoeic variant, implying a contributory role for mast cells in the aggressiveness of BCC.