Resection of a retroperitoneal lumbar vein aneurysm: A case report.

We present a rare case involving a 54-year-old man with a history of pancreatitis who developed a retroperitoneal lumbar vein aneurysm that was initially misidentified as a pancreatic pseudocyst. Subsequent imaging revealed an enlarged mass and retroperitoneal perforation. Despite initial hesitation, the patient eventually underwent radical surgery that enabled the successful removal of the mass, which was near the inferior vena cava. Pathological examination confirmed varicose veins, and the final diagnosis was lumbar vein aneurysm in the retroperitoneum. The patient's postoperative recovery was uneventful, with no symptoms or recurrence observed on 6-month follow-up imaging. We investigated a potential link between pancreatitis and recurrent bleeding due to weakened venous walls. The findings from this case underscore the rarity of venous aneurysms and the diagnostic and treatment challenges due to the limited number of cases; furthermore, they emphasize that surgery should be carefully considered based on the lesion location and associated risks.