Evaluation of computed tomography guided percutaneous biopsy of the pancreas.

The results of 96 computed tomography guided percutaneous pancreatic aspiration biopsies were reviewed to evaluate the diagnostic sensitivity, specificity and accuracy in pancreatic mass lesions. These were assessed by comparing pathology results to findings at subsequent laparotomy, autopsy or to immediate and long term clinical findings. Effects of varying the size of the biopsy needle and the number of aspirations performed were examined. Of the primary tumors of the pancreas in which adequate material was obtained, 97.3 per cent were correctly diagnosed with one false-negative and no false-positive results. The over-all sensitivity rate for primary tumor so the pancreas was 71.9 per cent using a No. 22 gauge "skinny" needle and 86.7 per cent using a No. 20 gauge needle. Over-all diagnostic accuracy for all types of lesions was 61.8 per cent using a No. 22 gauge needle and 73.3 per cent using a No. 20 gauge needle. A No. 19 gauge needle with a sheath was used on lesions with fluid or necrotic debris when a pseudocyst was a possibility. Over-all diagnostic accuracy using a No. 19 gauge sheathed needle was 81.8 per cent on all types of lesions. There was no benefit in using two passes versus a single aspiration. There were no complications, regardless of the needle size or number of passes. The serum amylase level increased in one instance after biopsy and this returned to normal a few days after biopsy. Computed tomography guided aspirations are safe and effective in evaluation of focal or diffuse enlargements of the pancreas when proper techniques and appropriate precautions are used.