An unusual sonographic appearance of a chronic renal peritransplant lymphocele.

Lymphoceles are the most common renal peritransplant collections. They typically develop and progress within 6 months of transplantation. Clinical presentation is varied and includes azotemia, lower extremity edema, fever, weight gain, tenderness over the allograft, palpable mass, and thromboembolic complications. Herein, we present a chronic peritransplant lymphocele with unusually thick and irregular internal septae which could easily be mistaken for other complex peritransplant or pelvic masses. In this case, color Doppler flow imaging helped to limit the differential diagnosis as well as to guide appropriate intervention. Additionally, we describe the pathophysiology of lymphocele formation and treatment options.