Ectopic Renal Ossification as Nucleus of Urinary Stones

Abstract
Areas of ectopic ossification were found in thin sections from 19 of 1624 [human] calculi submitted to a petrographic procedure, this represents an incidence of 1.16%. Only 8 calculi of renal pelvic or ureteral origin with osseous tissue in its structure have been described since the 1st report by Phemister in 1923.