Mast cell variations in tumour tissue and with histopathological grading in specimens of prostatic adenocarcinoma.

To determine whether the number of mast cells (MCs) varies in and around prostatic carcinoma tissue, and with histopathological grading. Specimens of 27 prostatic carcinomas were stained with the toluidine blue and staged histopathologically using the Gleason grading system. The MCs were counted in five high-power microscopy fields within and around the tissue samples, and the results analysed using the Wilcoxon signed-rank test and Spearman's correlation. The mean number of MCs was 1.7 per field within and 3.31 per field around the cancer tissue, the difference between these being significant (P<0. 05). There was a close correlation between the numbers of MCs within the tumour and Gleason grade (r=0.56, P=0.002) but not between grade and counts around the tumour (r=-0.18, P=0.35). These results suggest that some MCs aggregate at the periphery of the prostatic adenocarcinoma and that the number of MCs within the tumour tissue is related to tumour differentiation.