Bilateral acquired Perirenal Lymphangiectasia: case report.

Bilateral perirenal lymphangiectasia is a rare condition characterized by the dilation of lymphatic ducts and the formation of fluid-filled cavities. Renal lymphangiectasia is rarely observed, affecting approximately 1% of cases, with only 34 bilateral cases reported in adults by 2025. This case report discusses a 55-year-old male with a history of recurrent pyelonephritis who was eventually diagnosed with bilateral acquired perirenal lymphangiectasia based on CT, MRI, and cytochemical analysis of perirenal fluid. The patient exhibited mild left flank pain without further complications, and given the disease's benign nature, an expectant management approach was adopted. Follow-up assessments confirmed an asymptomatic status. This report highlights the importance of considering lymphangiectasia in differential diagnoses for renal cystic lesions to avoid unnecessary procedures. Our case is the 35th documented instance of bilateral renal lymphangiectasia in the literature, underscoring the need for medical awareness of this condition to improve diagnosis and patient care.