The present study retrospectively analyzed computerized tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography-computerized tomography (PET/CT) data to identify features that may distinguish pancreatic carcinoma (PC) from mass-forming chronic pancreatitis (MFCP) of the pancreatic head. The mean diameter of the lesions was larger in the MFCP patients (n=24) than in the PC patients (n=30; 5.44±27 vs. 3.34±1.23 cm; P<0.001). PC lesions showed increased lobulation when compared with the MFCP cases (83.33 vs. 12.5%; P<0.001). Lesions in the MFCP patients exhibited diffuse and marginally distributed calcification. MFCP patients showed increased exudation around the lesion (83.33 vs. 13.33%), pseudocyst formation (58.33 vs. 10%) and thickening of the right renal fascia (83.33 vs. 13.33%) than in the PC patients. MFCP patients also exhibited visible remnants of normal pancreatic tissue within the lesions. MFCP and PC patients could be distinguished by a cutoff value of 4.40 cm for lesion size [area under the curve (AUC): 0.894; 95% confidence interval (CI): 0.810-0.978)], 21.85 Hu for net-increased value in the arterial phase (AUC, 0.799; 95% CI, 0.670-0.928), 37.70 Hu for net-increased value in the portal phase (AUC, 0.798; 95% CI, 0.919-0.677), 4.85 for early standardized uptake value (SUV) of 18F-deoxyglucose (18F-FDG; AUC, 0.934; 95% CI, 0.850-1.018) and 4.90 for delayed SUV of 18F-FDG (AUC, 0.958; 95% CI, 0.878-1.038). These findings demonstrated that the integration of data from dynamic contrast-enhanced CT, MRI and PET/CT imaging may distinguish MFCP from PC.
Keywords: differential diagnosis; mass-forming chronic pancreatitis; multi-modality imaging; pancreatic head carcinoma; pancreatic head mass.