Ovarian Vein Syndrome Presenting as Recurrent Right-Sided Flank Pain: A Case Report.

Ovarian vein syndrome (OVS) is a rare cause of ureteral obstruction resulting from extrinsic compression by a dilated ovarian vein, most commonly affecting women of reproductive age. Its nonspecific presentation, including intermittent flank or abdominal pain, urinary symptoms, and recurrent UTIs, often mimics more common conditions such as ureterolithiasis, appendicitis, or gynecologic pathology, leading to delayed diagnosis. Imaging modalities, particularly contrast-enhanced CT, are essential for identifying dilated ovarian veins compressing the ureter and associated hydronephrosis. We report a case of a woman with recurrent right-sided abdominal and flank pain initially attributed to physiologic hydronephrosis during pregnancy, whose diagnosis of OVS was established years later after longitudinal imaging revealed a markedly dilated right gonadal vein causing ureteral compression. Management of OVS is individualized and may include conservative measures such as analgesia, hydration, and monitoring of renal function, or interventions such as endovascular embolization or surgical ligation in cases of persistent or progressive obstruction. This case highlights the importance of considering OVS in the differential diagnosis of unexplained unilateral hydronephrosis and recurrent flank pain, underscores the role of imaging in timely diagnosis, and demonstrates that conservative management can be effective in selected patients.