Mast Cells and Fibrosis

Abstract

The development of staining techniques for histologic sections led to the initial definitive description of mast cells by a medical student named Paul Ehrlich over 100 years ago. Although other investigators, including von Recklinhausen, 1 had previously described granular cells in the connective tissues of unstained tissue sections, the young Ehrlich was the first to recognize a distinct subset of cells containing granules that stained red or violet when treated with a blue basic aniline dye, dahlia. 2 Thus the metachromatic nature of these cytoplasmic granules drew Ehrlich's attention. He believed that cells containing these granules were overfed, and thus he referred to them as Mastzellen (in German, masten = to fatten). Ehrlich published in his doctoral thesis 3 the astute observations that connective tissue mast cells often surrounded nerves, blood vessels, and glandular ducts, and that mast cell numbers were increased in certain sites of inflammation and neoplasia.