Modification of Management Algorithm of Radiologically Suspected Pancreatic and Biliary Malignancy by Incorporation of Local Experience of Autoimmune Pancreatitis

Full Article

CYH Chan, DHS Fung, VWT Chan, OK Wong, SKY Kwok, WK Wong, KW Tang

Hong Kong J Radiol 2015;18:260-6

DOI: 10.12809/hkjr1515308

Objectives: To review the clinical and pathological features of autoimmune pancreatitis (AIP) in a tertiary referral centre in Hong Kong, and to determine preoperative factors that facilitate diagnosis of AIP in order to avoid Whipple’s procedure.

Methods: According to our pathology and radiology databases, 13 patients were diagnosed in our hospital with type 1 AIP from 1 January 2003 to 31 December 2013. Clinical, serological, radiological and histopathological features and treatment outcomes were analysed.

Results: The mean age of patients was 63.2 years with a male predominance (85%). Obstructive jaundice was the most common presenting symptom (69%). Serum immunoglobulin G4 (IgG4) was measured in 12 patients and was elevated in all cases. Focal pancreatic mass was the most common radiological manifestation (46%), followed by diffuse (31%) and segmental (23%) swelling of the pancreas. Subgroup analysis of subjects diagnosed only after surgery showed significant elevation of postoperative serum IgG4 level, with extrapancreatic manifestations present in two cases.

Conclusions: In this cohort, our AIP patients showed similar features with those in China and Taiwan, but different to those in Japan and Korea. A future large-scale multicentre cohort would help determine whether AIP manifests differently in different geographical locations. AIP can mimic pancreatic and biliary malignancies, thus radiologists should be familiar with its typical radiological features. Serum IgG4 should be measured and extrapancreatic manifestations looked for in patients who manifest with radiologically suspected pancreatic cancer or extrahepatic cholangiocarcinoma at the pancreatic level. Judicious use of endoscopic ultrasound-guided biopsy, endoscopic retrograde pancreatography, and steroid trial in selected cases would be valuable to exclude malignancy and confirm AIP. Some Whipple’s procedures can hopefully be avoided by these measures.

 

中文摘要

 

按本地對自身免疫性胰腺炎的診治經驗修改對懷疑胰腺和膽道惡性腫瘤患者的診治方法

陳彥豪、馮漢盛、陳偉達、黃安傑、郭啟欣、王旺根、鄧國穎

 

目的:回顧香港一所三級醫院內自身免疫性胰腺炎(AIP)患者的臨床和病理學特徵。並探討患者術前特徵以加快AIP診斷及避免Whipple手術。

方法:根據本院的病理和放射學資料庫,在2003年1月1日至2013年12月31日期間共有13宗AIP確診病例;按其臨床、血清學、放射學和組織病理學的特徵和治療結果進行分析。

結果:患者平均年齡63.2歲,男性居多(85%)。最常見的症狀是梗阻性黃疸(69%)。12名患者接受血清免疫球蛋白G4(IgG4)的檢測,水平升高。最常見的放射性表現為胰腺局部腫塊(46%),其次為胰臟瀰漫性腫大(31%)和節段性腫大(23%)。術後才被確診為AIP的患者術後血清IgG4水平顯著上升,其中兩例有胰外表現。

結論:本研究顯示本港AIP患者的表現特徵與中國大陸和台灣的患者相似,而與日本和韓國的患者有分別。進一步大型多中心研究將會有助於確定AIP患者的表現特徵是否在不同的地理位置有所不同。AIP與胰腺和膽道惡性腫瘤相似,因此放射科醫生必須掌握其影像學特徵。對於一些影像學懷疑胰腺癌或肝外膽管癌的病理,應測量病人的血清IgG4,並確定是否有胰外表現。審慎地使用內鏡超聲引導下穿刺活檢和內鏡逆行胰膽管造影,並在經揀選的情況下使用類固醇試驗治療,可以確診AIP和排除惡性腫瘤的可能性,並藉此避免Whipple手術。