Nodes and Soft Tissue Masses Involving the Retroperitoneum, Mesentery, Omentum, and Peritoneal Ligaments

Image-guided biopsy of retroperitoneal or mesenteric lesions has been shown to be accurate and safe. It can be performed using a range of imaging modalities, biopsy techniques, and devices. The differential diagnosis for disease involving the soft tissues of the retroperitoneum and the folds of the peritoneal cavity is diverse. Knowledge of the relevant anatomy and an understanding of the potential pathways of disease spread within and across these compartments can greatly enhance the radiologist’s ability to guide clinicians in the diagnosis and management of these disease processes.