Interaction between mast cells and perineurial fibroblasts in neurofibroma. New insights into mast cell function

Transmission electron microscopy was performed on seven neurofibromata to study the relationship between the frequently occurring mast cells and the other cell types present in the tumour. Intimate association was observed between mast cells and perineurial fibroblasts, but not between mast cells and Schwann cells. At the contact interface between mast cells and perineurial fibroblasts, numerous vesicle-like structures were observed with corresponding endocytotic vesicles in the fibroblast plasma membrane. The authors regard this close morphological relationship as in vivo evidence for a possible role of mast cells in fibroblast metabolism, a conclusion which has already been drawn from in vitro studies, but until now inadequately supported by observations in vivo.