Computerized tomography of retroperitoneal lymphadenopathy: benign or malignant.

A distinguishing feature has been noted to help differentiate between malignant retroperitoneal nodes and nodes which contain reactive hyperplasia. This sign is the presence of a cleavage plane between the mass of nodes and the great vessels which are easily visible in benign disease. This distinction is in reference to malignant nodal disease where the contours of the vessels are obscured. The ability to make a diagnosis of benign disease on CAT scan has enabled us to choose the appropriate course of therapy and, in some patients, allowed us to avoid exploratory laparotomy for diagnosis.