The differentiation of focal, chronic pancreatitis (CP) and pancreatic cancer (PAC) poses a diagnostic dilemma. Both conditions may present with the same symptoms and signs. The complexity of differential diagnosis is enhanced because PAC is frequently associated with secondary inflammatory changes and CP may develop into PAC. The aim of this study was tot analyze two sets of patients (group A and B) who were misdiagnosed to have either CP or PAC. The clinical and radiographical features of these patients were reviewed. Group A consisted of 22 patients (median age 54.5 years) who were referred with PAC after a previous diagnosis of PC. Eleven patients had a history of CP of > 12 mths (mean 40.2 mths) whereas in 11 patients, PAC became apparent within 12 mths (mean 4.9 mths) after the diagnosis of CP was made. The etiology of CP was alcohol abuse in 9 patients, pancreas divisum in 3 patients and was undefined in the remaining 10 patients. Imaging studies showed features of CP (parenchymal calcifications, irregularities and stenoses of the pancreatic duct wall). Pseudocysts were present in 13 patients. A mass lesion was detected in 13 patients. At the time of diagnosis, 20 patients had unresectable tumors and 2 patients underwent a Whipple resection which proved non-radical. Group B consisted of 14 patients (median age 53 years) who underwent a Whipple resection for a presumed PAC that on histopathology of the lesion proved to be CP. These patients accounted for 6% of all 220 patients who had undergone resection for PAC in the same period. Reassessment of clinical presentation and all imaging studies confirmed a high index of suspicion on PAC in these patients.
Conclusion: In patients known with CP, misdiagnosis of PAC is a potential pitfall leading to delay of treatment. For any lesion suspicious of PAC an aggressive surgical approach is justified lest a potentially curable lesion is missed. As a consequence, there is at least a 5% chance of resecting a lesion based on CP, mimicking PAC.