Association of mast cells with microvessel density in renal cell carcinomas.

Background: Growth of solid tumors requires angiogenesis. Evidence indicates that mast cells (MCs) play an important role in tumor angiogenesis. The aim of this study was to investigate the possible effects of angiogenesis and the presence of MCs on the prognosis of renal cell carcinoma (RCC).

Methods: Seventy-one patients who underwent radical nephrectomy for RCC were included in this study. Paraffin sections from tumor and nonneoplastic kidney were stained with CD31 antibody with the standard streptavidin-biotin immunperoxidase method. Microvessels were quantified by a stereologic method. Tumors and the surrounding area were also stained with toludine blue stain to show MCs in tumor and surrounding tissue. The correlation between microvessels and MC counts was evaluated and compared with tumor stage, grade, and other clinicopathologic parameters.

Results: MCs in RCC and peritumoral areas were observed to be greater than nonneoplastic kidney tissue. No correlation was found between MC number and various clinicopathologic features such as tumor size, stage, grade, and patient survival. No association was noted between angiogenesis and clinicopathologic features. On the other hand, significant correlation was found between the number of MCs and microvessel density (p=0.034, r=0.295).

Conclusion: Our results suggest that MC infiltration may contribute to tumor angiogenesis and acceleration of tumor growth, whereas stereologic assessment of angiogenesis does not help to predict biologic behavior in RCC. Further research is required to confirm these observations.