Comparison of clinical characteristics of radiological forms of autoimmune pancreatitis

Background

There is limited understanding of the clinical characteristics of different radiological forms of autoimmune pancreatitis (AIP). This retrospective study compared the clinical features of radiological forms of AIP.

Endoscopic ultrasonography findings in autoimmune pancreatitis

Endoscopic ultrasonography is an established diagnostic tool for pancreatic masses and chronic pancreatitis.In recent years there has been a growing interest in the worldwide medical community in autoimmune pancreatitis (AIP),a form of chronic pancreatitis caused by an autoimmune process.This paper reviews the current available literature about the endoscopic ultrasonographic findings of AIP and the role of this imaging technique in the management of this protean disease.     

EUS findings in patients with autoimmune pancreatitis

BACKGROUND: Autoimmune pancreatitis is an increasingly recognized benign condition with a presentation similar to pancreatic neoplasia but responds to corticosteroid therapy. Clinical features, ERCP, and CT findings have been described. This study assessed the EUS and EUS-guided FNA features of proven autoimmune pancreatitis. METHODS: The diagnosis of autoimmune pancreatitis was based on examination of surgical resection specimens or typical clinical findings (elevated immunoglobulin G level, no evidence of malignancy, characteristic non-EUS imaging studies, and clinical improvement, especially in response to treatment with a corticosteroid). RESULTS: Presenting manifestations in 14 patients included obstructive jaundice, abdominal pain, and weight loss. Ten patients underwent surgery (including exploratory surgery). Six were successfully treated with corticosteroid. EUS revealed diffuse hypoechoic pancreatic enlargement (8/14) or a focal irregular hypoechoic mass (6/14). Features of chronic pancreatitis were not noted. EUS-guided FNA of the pancreas was suggestive of chronic inflammatory pancreatitis in 9 of 12 patients. Celiac and peripancreatic lymphadenopathy (up to 3 cm in diameter) was present in 6 patients. EUS-guided FNA of lymph nodes (3/4) did not reveal evidence of malignancy. Vascular involvement was noted in 3 patients. CONCLUSIONS: The EUS features of autoimmune pancreatitis are easily mistaken for malignancy. However, a diffusely hypoechoic, enlarged pancreas, together with chronic inflammatory cells in aspirated cytologic specimens, is supportive of the diagnosis of autoimmune pancreatitis. When combined with clinical data, EUS and EUS-guided FNA may support a diagnosis of autoimmune pancreatitis, may warrant a trial of corticosteroid, and thereby may prevent unnecessary surgery.     

Comparison of clinical findings between histologically confirmed type 1 and type 2 autoimmune pancreatitis

Background and Aim: Type 2 autoimmune pancreatitis (AIP) has been reported mainly in Western countries and is thought to be very rare in Asia. The aim of this study was to compare the prevalence, clinical profiles, detailed radiological findings, and steroid responsiveness between type 1 and type 2 AIP in Korea. Methods: From 120 patients diagnosed with AIP between January 2003 and August 2010, 52 patients with histologically confirmed type 1 (n = 37) or type 2 (n = 15) AIP were included. Results: The median age of patients with type 2 AIP was significantly lower than that of patients with type 1 AIP (61 vs 34 years, P < 0.05). At initial presentation, severe abdominal pain and presentation with acute pancreatitis were more frequent in patients with type 2 AIP (P < 0.05). On computed tomography scan, the extent of pancreatic enlargement and the frequency of low‐density mass did not differ significantly between the two groups. Detailed pancreatographic findings on endoscopic retrograde cholangiopancreatography/magnetic resonance cholangiopancreatography were not significantly different between the two groups. All patients with steroids therapy improved clinically and radiologically in response (25/25 in type 1 AIP and 14/14 in type 2 AIP). During the follow‐up period, none of the patients with type 2 AIP experienced relapse. Conclusions: Type 2 AIP in all histologically confirmed AIP cases in Korea may not be as rare as originally thought, with an estimated prevalence rate of 28.8% (15/52). The detailed radiological findings of type 1 and type 2 AIP were not significantly different, and both subtypes responded well to steroids.     

Difficulty in diagnosing autoimmune pancreatitis by imaging findings

BACKGROUND: Autoimmune pancreatitis (AIP) presents as diffuse enlargement of the pancreas and as diffuse irregular narrowing of the main pancreatic duct. However, some AIP cases are difficult to diagnose because of atypical imaging findings. OBJECTIVE: To clarify a variety of imaging findings of AIP and the reason for its misdiagnosis. DESIGN: We examined the imaging findings of 37 AIP cases and also examined misdiagnosed cases of AIP to determine their reasons for misdiagnosis. PATIENTS: A total of 37 patients with AIP who reported to our hospital or its affiliate over a 17-year period (1989 to May 2005). RESULTS: Patients in 15 AIP cases showed segmental narrowing of the main pancreatic duct. There were 6 patients with focal enlargement of the pancreas, whereas 3 patients showed no enlargement. There were 3 cases of calcification of the pancreas. Pancreatic cysts were detected in 2 patients. Abdominal US showed multiple low-echoic masses in 1 case and a single mass in 3 cases. Sixteen patients had stenosis of the bile duct at the hilar hepatic lesion and/or the intrahepatic duct. Only 7 patients had typical AIP findings. Six patients were misdiagnosed with pancreatic cancer and 2 with bile-duct cancer. Seven cases were surgically treated. Five cases were misdiagnosed because of the nonexistence of, or the unfamiliarity with, the concept of AIP and sclerosing cholangitis with AIP. Another 3 cases were diagnosed with pancreatic cancer because of segmental stenosis of the main pancreatic duct and no or focal enlargement of the pancreas. CONCLUSIONS: The results of this study suggest that AIP presents a variety of imaging findings. The most important diagnostic factor is clinician awareness of the concept of AIP and the diverse nature of imaging findings.     

MRCP and MRI findings in 9 patients with autoimmune pancreatitis

AIM: To evaluate magnetic resonance cholangiopancre-atography (MRCP) findings in conjunction with magnetic resonance (MR) images in autoimmune pancreatitis (AIP) patients. METHODS: Nine patients with AIP underwent MRI, MRCP, endoscopic retrograde cholangiopancreatography (ERCP), computed tomography, and ultrasonography. The MRCP and MR images taken before and after steroid therapy were reviewed and compared with other imaging modalities. The MRCP findings of the AIP cases were compared to those of 10 cases with carcinoma of the head of the pancreas. RESULTS: On MRCP, the narrowed portion of the main pancreatic duct noted on ERCP was not visualized, while the non-involved segments of the main pancreatic duct were visualized. The degree of upstream dilatation of the proximal main pancreatic duct was milder than that seen in cases of pancreatic carcinoma. Stenosis or obstruction of the lower bile duct was detected in 8 patients. MR images showed enlargement of the pancreas with decreased signal intensity on T1-weighted MR images, increased signal intensity on T2-weighted MR images, and, in 3 patients, a hypointense capsule-like rim. After steroid therapy, the previously not visualized portion of the main pancreatic duct was seen, along with improvement of the bile duct stenosis. Pancreatic enlargement decreased, and the abnormal signal intensity on both T1- and T2-weighted MR images became isointense. CONCLUSION: MRCP cannot differentiate irregular narrowing of the main pancreatic duct seen with AIP from stenosis of the main pancreatic duct seen with pancreatic carcinoma. However, MRCP findings in conjunction with MR imaging of pancreatic enlargement that shows abnormal signal intensity on T1- and T2-weighted MR images are useful in supporting a diagnosis of AIP.     

Comparison of clinical findings between autoimmune pancreatitis with bile duct involvement and primary sclerosing cholangitis]

BACKGROUND/AIMS: The involvement of bile ducts is frequently reported in autoimmune pancreatitis (AIP), which seem to have similar features to primary sclerosing cholangitis (PSC). Recent systematic comparative studies about these diseases are rare in Korea. METHODS: We retrospectively analyzed 26 patients with AIP with bile duct involvement and 30 patients with classic PSC who were diagnosed during the last decade. RESULTS: The mean age of patients was significantly higher in AIP than PSC at the time of diagnosis. There was a preponderance of men in both group, which was more prominent in AIP. The most common symptom in patients with AIP was jaundice, but PSC patients usually visited hospitals due to incidentally detected abnormal liver function tests. Most (26/31) of AIP had bile duct involvement. All of these patients showed narrowing of intrapancreatic common bile ducts and one patient exhibited hilar involvement as well. About 80% of PSC had both intra- and extrahepatic ducts involvement, and the characteristic features involve multifocal strictures. AIP patients showed improvement with steroid treatment, however, most PSC patients showed clinical deterioration. CONCLUSIONS: The clinical and cholangiographic findings of patients with AIP and PSC have many different characteristics. Therefore, further study of two diseases is required for the proper diagnosis and management.     

自身免疫性胰腺炎与小胰腺癌的CT、MRCP征象分析

目的 分析自身免疫性胰腺炎(AIP)与小胰腺癌的CT、MRCP影像学征象的差异,提高对AIP的认识及诊断的准确率.方法 回顾性分析符合2008年AIP亚洲诊断标准的24例AIP及病理证实的25例小胰腺癌(≤2 cm)的影像学资料,从胰腺的形态改变、密度及强化方式、胰管及胰周、胰外表现等方面进行比较,采用×2检验或确切概率法行统计学处理.结果 在AIP和小胰腺癌组间,肿块部位、远端胰腺萎缩、肿块持续强化、胰管“截断征”、“鞘膜征”及肾脏受累征象差异具有统计学意义(x2 =9.010、10.506、15.288、8.688、6.292和4.966,P＜0.05),但是只有远端胰腺萎缩和肿块持续强化征象在局限性AIP与小胰腺癌组间差异具有统计学意义(P＜0.05).结论 弥漫性AIP的影像学改变具有特异性,与小胰腺癌容易鉴别诊断,但局灶性AIP与小胰腺癌鉴别诊断价值有限.     

肿块型自身免疫性胰腺炎与胰腺导管腺癌的超声及超声造影表现分析

目的 探讨超声及超声造影对肿块型自身免疫性胰腺炎（AIP）与胰腺导管腺癌（PDAC）的鉴别诊断价值。方法 回顾性分析2015年1月—2020年12月唐山市工人医院确诊的11例肿块型AIP患者的临床资料及常规超声、超声造影资料,分析其特征性表现,并与23例PDAC患者的资料进行对比,计数资料两组间比较采用χ²检验。结果 11例肿块型AIP超声造影的诊断准确性为63.64%,均为单发病灶,且均低回声,在边界清晰、形态规则、胰管扩张或截断、血流信号方面所占比例分别为54.55%、63.64%、18.18%、36.36%,而PDCA组分别为30.43%、34.78%、78.26%、21.74%,两组间是否伴胰管扩张或截断方面存在统计学差异（χ²=11.089,P<0.05）,其余指标均无明显统计学差异（P值均>0.05）。超声造影中7例（63.64%）肿块型AIP动脉期呈高增强,4例（36.36%）呈等增强,静脉期5例（45.45%）呈高增强、6例（54.55%）呈等增强;23例PDAC中22例（95.65%）病灶在动脉期及静脉期均呈低增...     

Pseudoaneurysms and bleeding pseudocysts in chronic pancreatitis: radiological findings and contribution to diagnosis in 8 cases

Pseudoaneurysms and bleeding pseudocysts are rare but life-threatening complications of chronic pancreatitis. This report summarizes our experience in 8 cases collected from among 250 patients admitted for chronic pancreatitis. We describe the radiological findings of nine vascular lesions and especially emphasize the contribution of recent radiological imaging, ultrasound and computed tomography scanning in establishing the diagnosis of vascular complication. We also report a case of successful embolization of a splenic pseudoaneurysm that ruptured into the colon.     

Differentiation between autoimmune pancreatitis and pancreatic carcinoma based on endoscopic retrograde cholangiopancreatography findings

Objective  

We have reviewed the endoscopic retrograde cholangiopancreatography (ERCP) images of patients with autoimmune pancreatitis (AIP) and pancreatic carcinoma (Pca) in an attempt to identify findings that would facilitate making a differential diagnosis between AIP and Pca.