Follicular Lymphoma Recurrence Presenting as Unilateral Leg Swelling and Ipsilateral Hydronephrosis

A 73-year-old man with a history of follicular lymphoma ten years ago with complete remission presented to the emergency room with a large unilateral left-leg swelling as the only symptom. Doppler ultrasonography ruled out deep vein thrombosis. Bedside point-of-care ultrasound (PoCUS) revealed left moderate hydronephrosis. A CT of the abdomen showed a bulky soft tissue mass in the region of the distal left psoas muscle. The mass was generating an extrinsic compression of the left ureter and venous system. The histological study of the lesion established the diagnosis of follicular lymphoma recurrence. The patient subsequently received immunochemotherapeutic treatment in the oncological treatment center. This case report is intended to promote awareness about a possible clinical correlation between unilateral leg swelling and hydronephrosis with a compressive intra-abdominal mass.