Tubular cell emboli in the glomerulus--a needle biopsy artifact

In a needle biopsy specimen of the kidney, epithelial cells were found within the capillaries of a single glomerulus. These proved to be proximal tubular epithelial cells with their typical nuclei, mitochondria, lysosomes, junctional complexes, and brush border. Similar cells were also found in Bowman's space. This is an artifact of the needle biopsy in which tubular cells or cell fragments had been detached from the tubule by the needle and then pushed through the cut end of an arteriole into the glomerular capillaries and to Bowman's space.