A feasible CT feature to differentiate focal-type autoimmune pancreatitis from pancreatic ductal adenocarcinoma.

Chaobin He,Qian Cai,Shengping Li,Wanming Hu,Yanchun Lv,Qiuxia Yang,Rong Zhang,Yize Mao,Dailin Rong

doi:10.1002/cam4.2526

Chaobin He, Qian Cai + Show 7 more

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https://doi.org/10.1002/cam4.2526

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Abstract

BackgroundTo investigate whether the relative computed tomography (CT) value (rCT) of adjacent pancreatic parenchyma can distinguish focal‐type autoimmune pancreatitis (fAIP) from pancreatic ductal adenocarcinoma (PDAC).MethodsA total of 13 patients with fAIP and 20 patients with PDAC were included in this study. The rCT was calculated as the ratio of the CT value of adjacent pancreatic parenchyma to that of muscle. The diagnostic performance of rCT for discriminating fAIP from PDAC was evaluated using receiver operating characteristic (ROC) analysis.ResultsBoth fAIP and PDAC presented hyper‐fibrosis histologically and delayed enhancement on CT examination. Moreover, the pancreatic parenchyma of fAIP presented serious inflammation. The mean rCT of the parenchyma was significantly lower in fAIP than in PDAC in all phases. The best diagnostic performance of the rCT value was found in the pancreatic phase, with an area under the ROC curve of 0.912, while the areas under the ROC curve of the portal and delayed phases were 0.812 and 0.754, respectively. The optimal cut‐off value for distinguishing fAIP from PDAC was 1.62 in the pancreatic phase.ConclusionsThe rCT of the pancreatic parenchyma during the pancreatic phase may be a feasible CT feature for differentiating fAIP from PDAC.

Highlights

Autoimmune pancreatitis (AIP) is a unique form of pancreatitis with abundant pathological lymphoplasmacytic infiltration pathologically.[1,2] Recent studies have classified AIP into two groups: the diffuse and focal subtypes.[3,4] focal‐type autoimmune pancreatitis, accounting for approximately 33%‐41% of all cases, shares similar features with pancreatic ductal adenocarcinoma (PDAC); the features include focal or mass‐like enlargement of the pancreas and obstructive jaundice.[3,5,6] the treatment of fAIP and PDAC is completely different
This study sought to analyze the enhanced characteristics of adjacent pancreatic parenchyma in fAIP and PDAC, and we found that the computed tomography (CT) attenuation value of the adjacent pancreatic parenchyma in the pancreatic phase was significantly lower in patients with PDAC than in those with fAIP
Recent studies revealed that both fAIP and PDAC present as delayed enhancements during the portal and delayed phases,[4,8,9,10,11] which was observed in our study

Summary

| INTRODUCTION

Autoimmune pancreatitis (AIP) is a unique form of pancreatitis with abundant pathological lymphoplasmacytic infiltration pathologically.[1,2] Recent studies have classified AIP into two groups: the diffuse and focal subtypes.[3,4] focal‐type autoimmune pancreatitis (fAIP), accounting for approximately 33%‐41% of all cases, shares similar features with pancreatic ductal adenocarcinoma (PDAC); the features include focal or mass‐like enlargement of the pancreas and obstructive jaundice.[3,5,6] the treatment of fAIP and PDAC is completely different. Similar imaging features such as regional enlargement of the pancreas and delayed enhancement cause challenges in differentiating fAIP from PDAC.[4,8,9,10,11] An estimated 3%‐9% of fAIP patients have been reported to undergo resection for a presumed carcinoma.[12] accurate diagnosis of fAIP vs PDAC is critical. Our study retrospectively analyzed the enhanced computed tomography (CT) features of adjacent pancreatic parenchyma in fAIP and PDAC patients and evaluated whether the enhancement of the adjacent pancreatic parenchyma of the two conditions could differentiate fAIP from PDAC

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Findings

| DISCUSSION