label: Phlebolith
label_lc: phlebolith
description: "A calcified structure that forms within a vein. The pathogenesis of phleboliths is thought to involve an organized thrombus produced when the peripheral blood flow slows. The thrombus calcifies, form- ing the core of the phlebolith. Then, the fibrinous com- ponent undergoes secondary calcification and becomes attached. Repetition of this process causes enlargement of the phlebolith."