Figure 1: (A-D) Technique of hydro-dissection performed in prone position. Unenhanced CT image (A) shows retroperitoneal lymph node (yellow arrow) medial to aorta (red arrow). Unenhanced CT image (B) shows sleeve of saline injected to displace endo-thoracic fascia and aorta laterally. Enhanced CT image acquired by injection of 40ml of iodinated contrast (C) shows the needle carefully transfixing the lymph node; image (D) CT axial section in lung window shows no pneumothorax. The biopsy was safely performed, confirming the diagnosis of Granulation tissue.