Background and aim: Indeterminate pancreatic head mass in chronic calcific pancreatitis is a management dilemma often faced by surgeons. The aim of this study was to identify factors that could assist in distinguishing between malignant and inflammatory pancreatic head lesions arising in patients with chronic pancreatitis.
Patients and Methods: Retrospective chart review of 250 patients presenting to the pancreas clinic over 6 years (from January 2000 to December 2005), with chronic pancreatitis (symptomatic with presence of intraparenchymal or intraductal calcifications or dilated pancreatic duct). Of this 49 had a pancreatic head or uncinate mass (defined as a mass lesion >3cm) on CT scan. Seven additional patients with obvious metastasis were excluded. Most of the patients (42/49) had tropical nonalcoholic Pancreatitis. Patients were divided into Group I (Malignant n=17) where the diagnosis was confirmed on percutaneous cytology (7), laparotomy and biopsy in 6 or on evidence of metastases at follow up or death in 4; and Group II (benign group n=32) where operative specimens confirmed benign histology (Whipple=3, Frey =7, Hepaticojejunostomy =1) or patients were doing favourably on non- interventional follow up (n =21).The groups were compared for clinical presentation, biochemical factors, and radiology.
Results: On univariate analysis, features which could predict malignant lesions were total bilirubin ≥3mg/dl (p=.001, sensitivity 68%, specificity 81%), alkaline phosphatase ≥200 IU/L (p=.006, sensitivity 68%, specificity 75%), CA 19-9 ≥50 Units/ml (sensitivity 100%, specificity 62%). At cutoff lvels of 200 units/ml for CA 19-9, only 12% of malignancies were missed, while only 17% in benign group had >200. Presence of vascular invasion was also strongly suggestive of malignancy. Recent loss of weight tended to be commoner in the malignant group, but recent aggravation of pain or diabetes was not significantly dissimilar between the two groups. However, multivariate analysis did not show significant difference between the two groups, perhaps because of inadequate sample size.
Conclusion: In patients with chronic pancreatitis and an indeterminate head mass, elevations of CA 19-9 bilirubin and alkaline phosphatase values and presence of vascular invasion may be useful in diagnosing malignant lesions.