Background/aims: There is more potential for misclassification of adenocarcinoma of the pancreas than for many other cancers because of the difficulty of accurate diagnosis.
Methodology: We analyzed the clinicopathological features of 105 patients who were suspected of having unresectable adenocarcinoma of the pancreas on their 1st visit to our outpatient clinic.
Results: Ten of 105 patients (10%) had been misdiagnosed as having pancreatic carcinoma. The final diagnoses were made mainly using dynamic computed tomography (CT) and/or histologic examination. The incidence of weight loss (> or = 7% of total-body weight, within 6 months before diagnosis) in the misdiagnosed patients was significantly lower than that in pancreatic carcinoma patients (30% vs. 67%, p=0.02). Serum CA19-9 abnormality (> 100 U/ml) was observed less frequently in the misdiagnosed patients than in the patients with pancreatic carcinoma (40% vs. 77%, p=0.01). The detection of a dilated main pancreatic duct and/or pancreatic mass by imaging modalities was less frequent in the misdiagnosed patients (p<0.01).
Conclusions: Dynamic CT and/or histologic examination may be essential when making a definite diagnosis of advanced pancreatic carcinoma. In addition, weight loss, serum CA19-9 abnormality, detection of a dilated main pancreatic duct and/or pancreatic mass may also be useful in making a differential diagnosis of this disease.