Jackstone Calculus: A Rare Subtype of Urinary Stone with a Sea-Urchin Appearance

Abstract

Most of bladder calculi are mobile, though stones formed on a suture or retained stent or on the intravesical portion of a papillary tumor are fixed. Generally, most of urinary calculi are calcium oxalate dehydrate monohydrate stones with a regular, homogeneous appearance and smooth margin. During endoscopic examinations they appear black, whereas Jackstone calculi are irregular and yellow [2]. Calcium oxalate dehydrate monohydrate stones are less susceptible to fragmentation through lithotripsy.