Pelvic phleboliths are common calcifications that form within the veins of the pelvis, often discovered incidentally during medical imaging. Sometimes referred to as “vein stones,” they occur with increasing frequency as people age and are estimated to be present in up to 48% of adults over 40 years old.
What Exactly Are Pelvic Phleboliths?
The term “phlebolith” literally translates from Greek to “vein stone.” A phlebolith begins as a small blood clot (thrombus) that forms within a vein, typically where blood flow is slow or stagnant, such as in the pelvic veins. Over time, this clot undergoes calcification, where minerals like calcium carbonate and calcium phosphate are deposited. This mineralization hardens the clot, creating a stable, rounded mass visible on imaging studies like X-rays or CT scans. These calcified masses usually measure between 2 and 5 millimeters in diameter, and their formation is often associated with factors that increase pressure in the pelvic veins, such as chronic constipation or pregnancy.
The Primary Question: Do Phleboliths Resolve or Go Away?
Pelvic phleboliths do not naturally dissolve or go away once they have fully developed. This lack of resolution is directly related to their composition as dense, calcified structures, representing stable mineral deposits that are biologically inert. Once the initial blood clot has hardened and mineralized, the resulting phlebolith becomes a permanent fixture in the vein. The body lacks a mechanism to break down and absorb such a dense deposit, meaning the calcification remains stable and typically remains visible on imaging for the rest of a person’s life.
Clinical Significance and When They Cause Symptoms
The vast majority of pelvic phleboliths are entirely asymptomatic and are found incidentally, meaning they do not cause any pain or health problems. Their discovery is usually considered a normal variant or a sign of vascular aging. Clinically, the main concern is distinguishing them from other calcifications, particularly ureteral stones, which cause severe pain and can be confused with phleboliths on initial imaging. While phleboliths rarely cause symptoms, multiple phleboliths may occasionally be part of a larger, slow-flow vascular anomaly or venous malformation, such as Pelvic Congestion Syndrome. In these cases, any pelvic discomfort is attributed to the underlying venous condition, not the phleboliths themselves.
Management and Monitoring
For asymptomatic and clearly identifiable pelvic phleboliths, no specific treatment is necessary. The standard approach is to confirm the diagnosis and reassure the patient about the benign nature of the finding. Since these calcifications do not dissolve and do not cause symptoms, routine monitoring or follow-up imaging is unnecessary. If a phlebolith is difficult to differentiate from a ureteral stone, further imaging, such as a CT scan utilizing the “comet-tail sign,” may be used to confirm its venous origin. Treatment is only pursued if the phleboliths are linked to a symptomatic underlying condition, such as a painful venous malformation, focusing on treating the underlying condition rather than the phlebolith itself.