Abstract
A study has been made of mast cells (MC) in surgically resected appendices using a long toluidine blue (LTB) staining method. The numbers of MC in measured areas of both mucosa and submucosa/muscularis were counted and comparisons made between 22 appendices containing threadworms and 22 which were histologically normal. There was considerable variation in MC numbers from case to case and the patients aged under 15 as a group had a higher mean number of mucosal MC than the older patients. The reasons for the high individual variation could not be identified from the histological sections, and no correlation was found between MC numbers and the presence of threadworms.