Abnormal Bowman space morphology Glomerular crescent formation 2020-11-29T13:27:03Z The crescent is an unspecific histopathological lesion that can be triggered by a variety of different underlying disorders. Whenever, microvascular injury leads to rupture of the glomerular basement membrane (GBM), the leakage of plasma proteins drives parietal epithelial cell hyperplasia as the key cellular component of the crescent. Single nephron GFR decreases because of tuft collapse, rupture of the Bowman capsule, and influx of immune cells and fibroblasts are all secondary events that may or may not occur in individual glomeruli. Periglomerular immune cell infiltrates or fibrotic encasting of the activated parietal cells (fibrocellular crescents) are subsequent events that may affect the dynamics and prognosis of the disease. Glomerular crescent refers hyperplastic lesions involving 10% or more of the circumference of Bowman's capsule. Crescents can be composed of a variable mixture of epithelial/leukocyte hypercellularity, fibrous matrix, and fibrin.