Gonadal vein phlebolith simulating a midureteral stone

Suprapelvic phleboliths: prevalence, distribution and clinical associations

The preliminary radiographs of 783 patients undergoing excretory urography were prospectively surveyed for the presence of abdominally located phleboliths. Two per cent demonstrated typical densities in a periureteral distribution flanking the lumbar spine where they could be confused with ureteral calculi. All these patients were multiparous females and three-quarters of them had pelvic masses (11% of all patients with pelvic masses), suggesting a possible association with gonadal vein thrombi. Altered venous flow with dilatation of ovarian veins, consequent valvular incompetence and stasis may account for the gonadal vein distribution in the pelvic mass cases. Other observed clinical conditions included hepatic disease, portal hypertension and varices. Obstruction and stasis of venous flow in hepatic disease states may lead to phlebolith formation in gastric and mesenteric varices. Unlike pelvic phleboliths, suprapelvic phleboliths are infrequent but may be detected by careful inspection of low kilovoltage films, particularly in the regions closely flanking the lumbar spine. Their presence may be associated with pelvic masses or significant chronic hepatic disease and they may be confused on plain film with ureteral calculi.