Value of biopsy in the assessment of a retroperitoneal mass

Aims: A retroperitoneal mass arising outside a specific organ usually gives rise to diagnostic uncertainty. Because of this, many clinicians request a radiologically guided biopsy. The aim of this study was to compare clinical and radiologic assessment with and without biopsy in patients undergoing surgical resection of a large abdominal mass. Methods: All patients undergoing resection of a large retroperitoneal mass under the care of one surgeon between 1994 and 2004 were included in this study. Results: One hundred and twenty-one patients underwent resection of a large retriperitoneal mass, of whom 84 had primary disease (median size 20cm, range 7cm-40cm). Thirty-six had clinical and radiologic assessment with biopsy while 48 had no biopsy. In the biopsy group four patients had a false negative result while two had a false positive result for a malignant tumour. Three patients had incorrect malignant histology on biopsy which led to an error in management in two. In addition, two adverse events related to biopsy were observed. One patient in the no biopsy group had an error in management. Sensitivity for diagnosis of a soft tissue tumour was 80.8% (95% Cl 69.5%-92.1%) for clinical and radiologic assessment alone versus 91.6% (95% Cl 82.6%-100%) when biopsy was added, Conclusions: Biopsy adds no value to clinical and radiologic assessment of the patient with a resectable large retroperitoneal mass