Atypical enhanced computed tomography signs of pancreatic cancer and its differential diagnosis from autoimmune pancreatitis

Abstract

Background: To analyze the atypical enhanced computed tomography (CT) signs of pancreatic cancer (PC) and compare them with those of autoimmune pancreatitis (AIP) to explore the differential diagnosis value of CT.

Methods: The clinical data of 36 AIP (AIP group) and 38 PC patients (PC group), who were admitted to our hospital from January 2013 to June 2020 and confirmed by surgical biopsy or hormone therapy, were retrospectively analyzed. Participants in both groups were examined by CT, the imaging signs of the 2 groups were analyzed, and the results of CT examination were compared.

Results: In the PC group, the density of the lesions on the CT scan was mostly reduced, the pancreas was not swollen, and the kidneys were not involved. The bile duct wall was thickened with a sausage-like appearance, enveloped edges were rare, blood vessels were invaded, lymph nodes were enlarged, and the pancreatic duct was truncated. The findings of the AIP group were the opposite. The difference in the proportion of participants with the above-mentioned CT features between the 2 groups was statistically significant (P<0.05). The shape of the lesions in the AIP group was mainly elongated, of uneven density, and the density of enhanced scanning was medium to high. The predominant shape of the lesions in PC participants was spherical, and the density was uniform. The enhanced scan was mainly low-density. The difference in shape and density between the 2 groups was also statistically significant (P<0.05). The CT values of the plain scan, intravenous phase, and delayed phase in the AIP group were significantly higher than those in the PC group (P<0.05).

Conclusions: The imaging signs of AIP and PC overlap. Examination with CT is of great value in the differential diagnosis between AIP and PC. Familiarity with and mastery of the CT signs of AIP and PC can help to improve the accuracy of clinical diagnosis and provide a reliable basis for patients' follow-up treatment.

Keywords: Autoimmune pancreatitis (AIP); differential diagnosis; imaging signs; pancreatic cancer (PC).

Figure 1

The results of CT scan. (A,B) The AIP CT scan shows pancreatic enlargement, the body tail is obvious, boundary is blurred, parenchymal density is slightly reduced, and the body tail is surrounded by a slightly low-density shadow. (C,D) The AIP enhanced scan for the late arterial phase, the pancreas is slightly enhanced and the density is slightly uneven. (E,F) Enhanced scan for the portal vein stage, the pancreas shows uneven enhancement, which is significantly lower than that of the liver, and thin strips of low-density shadows are seen inside. CT, computed tomography; AIP, autoimmune pancreatitis.