MAST-CELL ASSOCIATION WITH COLLAGEN-FIBERS IN HUMAN BREAST STROMA

Whirl-like structures consisting of strands and bundles of collagen fi bres with a central space are described in human breast stroma. Associ ation between these structures and connective tissue mast cells is dem onstrated. Mast cells in these whirls, in contrast to those in loose c onnective tissue, showed signs of secretory activity. On ultramicrosco py some showed electron-dense bud-like structures at the edge of the c ell, and between this and adjacent collagen bundles. In the absence of cytoplasmic cover association was demonstrated between the surface of a mast cell granule and a band of collagen fibres in the stroma. In v itro production of collagen fibres was reported in 1952 on the additio n of heparin powder to soluble collagen. The mechanism of that reactio n was not further defined. Neither, as yet, is that underlying the pre sent findings. The products of mast cell granules would appear to be c ommon to both. It is suggested that these findings may represent an al ternative pathway for collagen deposition in vivo, as in vitro.