<prompt> Crescents are derived from-Epithelial cells fibrin macrophageMesangium fibrin macrophageTubule mesangiaum fibrinMesangiaum fibrin  <response>: The glomeruli show cellular proliferation outside the capillary loops, sometimes in association with segmental capillary necrosis, breaks in GBM, and deposition of fibrin in Bowmans space. These distinctive proliferative lesions outside the capillary loops are called crescents owing to their shape as they fill Bowmans space. Crescents are formed both by the proliferation of epithelial cells and by the migration of monocytesmacrophages into Bowmans space. Smaller numbers of other types of leukocytes also may be present. Ref: ROBBINS BASIC PATHOLOGY 10th ed Pg no: 563 