Nat. Rev. Nephrol. doi:10.1038/nrneph.2016.101 Figure 3 Bellini duct plugs with overgrowths in patients who formed calcium stones Figure 3 | Bellini duct plugs with overgrowths in patients who formed calcium stones. a | Sites of crystalline deposits that form plugged Bellini ducts with an overgrowth region protruding into the urinary space. b | Endoscopic image of a plug (large arrow) protruding from a dilated Bellini duct (small arrows). Bellini duct plugs with overgrowths visible by light microscopy and micro-CT from c | a patient with idiopathic hydroxyapatite stones, d | a patient with idiopathic brushite stones, e | a patient with ileostomy, f | a patient with primary hyperparathyroidism, and g | a medullary sponge kidney. The curved, dotted lines divide the plugs from the overgrowth regions. Coe, F. L. et al. (2016) Idiopathic hypercalciuria and formation of calcium renal stones Nat. Rev. Nephrol. doi:10.1038/nrneph.2016.101