Tissue embolism is a near-equivalent to cancer metastasis, which happens when cancer tissue infiltrates blood vessels, and small fragments of them are released into the blood stream. Foreign-body embolism happens when exogenous—and only exogenous—materials such as talc enter the blood stream and cause occlusion or obstruction of blood circulation. Bullet embolism occurs in approximately 0.3% cases of gunshot wounds.[5] Amniotic-fluid embolism is a rare complication of childbirth.