Renal epithelial fragments of collecting duct origin are composed of three or more cuboidal cells. These fragments indicate a more severe form of renal tubule injury with basement membrane disruption. Proximal and distal convoluted tubule renal epithelial cells are not found in fragment form. In addition to the indication of severe tubule damage, proper identification of these fragments is important to avoid a false positive diagnosis of low-grade transitional cell carcinoma. Transitional cell carcinoma is a type of cancer seen in 71% of cases of malignant tumors of the ureter.