A hypoechoic, tumor-like lesion in the pancreatic head and neck on endoscopic ultrasonography may be due to a high-grade pancreatic intraepithelial neoplasia/carcinoma in situ
- Carcinoma in situ; endoscopic ultrasonography; focal pancreatic parenchymal atrophy; hypoechoic stricture; serial pancreatic juice aspiration cytological examination
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High-grade pancreatic intraepithelial neoplasia (HG PanIN)/carcinoma in situ (CIS) in the pancreatic body and tail can induce parenchymal atrophy through chronic inflammatory changes presenting as a Hypoechoic area on EUS (Hypocho) or focal pancreatic parenchymal atrophy (FPPA) on computed tomography (CT) and magnetic resonance imaging (MRI). We herein discussed two patients with a hypoechoic area in the pancreatic head and neck on EUS resembling pancreatic ductal adenocarcinoma (PDAC). The lesions consisted of dense fibrosis and fat infiltration with pancreatic parenchymal atrophy around the HG PanIN/CIS in the main pancreatic duct (MPD), which penetrated the lesion and showed mild stenosis and upstream dilation. CT and MRI were unable to visualize the lesions. A specimen was obtained from one lesion by fine-needle aspiration under EUS (EUS-FNA) guidance for histopathological and cytological analysis, but the tests returned negative for adenocarcinoma. However, serial pancreatic-juice aspiration cytologic examination (SPACE) revealed adenocarcinoma in both lesions, prompting surgical resection. Histopathological examination revealed non-invasive HG PanIN/CIS in the MPD surrounded by dense fibrosis and fat deposition in the area of parenchymal atrophy. The CIS was restricted to the area of parenchymal atrophy.These two cases are noteworthy in illustrating a hypoechoic area appearing on EUS as a tumor-like lesion resembling PDAC. EUS-FNA has recently been used histopathologically to diagnose a pancreatic lesion. However, in the present and similar cases, EUS-FNA can only reveal secondary changes due to CIS unless the pancreatic duct covered by the CIS is accidentally punctured. We should bear in mind that CIS can appear as a hypoechoic area resembling PDAC on EUS, and that SPACE is the best method for diagnosing CIS in such cases.
- Ilic M, Ilic I. Epidemiology of pancreatic cancer. World J Gastroenterol 2016; 22: 9694-705.
- Ansari D, Tingstedt B, Andersson B, et al. Pancreatic cancer: yesterday, today and tomorrow. Future Oncol 2016; 12: 1929-46.
- Kanno A, Masamune A, Hanada K, et al. Multicenter study of early pancreatic cancer in Japan. Pancreatology 2018; 18: 61-7.
- Harinck F, Konings ICAW, Kluijt I, et al. A multicenter comparative prospective blinded analysis of EUS and MRI for screening of pancreatic cancer in high-risk individuals. Gut 2016; 65: 1505-13.
- Luz LP, Al-Haddad MA, Sey MSL, et al. Application of endoscopic ultrasound in pancreatic cancer. World J Gastroenterol 2014; 20: 7808-18.
- Hruban RH, Goggins M, Parsons J, et al. Progression model for pancreatic Cancer. Clin Cancer Res 2000; 6: 2969-72.
- Kikuyama M, Hanada K, Ueki T. Pancreatic carcinoma in situ presenting prominent fatty change of the pancreatic body on CT: Experiences from 3 cases. J Jpn Pancreas Soc 2015; 30: 626-32. (in Japanese with English abstract).
- Satoh T, Kikuyama M, Kawaguchi S, et al. Acute pancreatitis-onset carcinoma in situ of the pancreas with focal fat replacement diagnosed using serial pancreatic-juice aspiration cytologic examination (SPACE). Clin J Gastroenterol 2017; 10: 541-5.
- Kuruma S, Kikuyama M, Chiba K, et al. Carcinoma in situ of the pancreas with pancreatic duct stricture persistent for 4 years diagnosed by serial pancreatic juice aspiration cytologic examination (SPACE). Clin J Gastroenterol 2020; 13: 443-7.
- Nakahodo J, Kikuyama M, Nojiri S, et al.?Focal parechymal atrophy of pancreas: An important sign of underlying high-grade pancreatic intraepithelial neoplasia without invasive carcinoma, i.e., carcinoma in situ. Pancreatology
- Terada S, Kikuyama M, Kawaguchi S, et al. Proposal for Endoscopic Ultrasonography Classification for Small Pancreatic Cancer. Diagnostics (Basel) 2019; 9: 15.
- Iiboshi T, Hanada K, Fukuda T, et al. Value of cytodiagnosis using endoscopic nasopancreatic drainage for early diagnosis of pancreatic cancer: establishing a new method for the early detection of pancreatic carcinoma in situ. Pancreas 2012; 41: 523-9.
- Izumi Y, Hanada K, Okazaki A, et al. Endoscopic ultrasound findings and pathological features of pancreatic carcinoma in situ. Endsco Int Open 2019; 07: E585-93
- Schima W, Böhm G, Rösch CS, et al. Mass-forming pancreatitis versus pancreatic ductal adenocarcinoma: CT and MR imaging for differentiation. Cancer Imaging 2020; 20:52