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Increased 18F-FDG uptake of heterotopic pancreatitis in the small intestine

A CARE-compliant case report

Ruan, Maomei MDa,b; Liu, Min MDa; Cheng, Lingxiao MDa; Xie, Wenhui MD, PhDb; Chen, Libo MD, PhDa,*

Section Editor(s): Zakko., Saad

doi: 10.1097/MD.0000000000004465
Research Article: Clinical Case Report
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Backgroud: Heterotopic pancreas (HP), a relatively uncommon congenital anomaly, is rarely noted during 18F-FDG positron-emission tomography/computed tomography (PET/CT) scan.

Methods: A 60-year-old woman was referred to our hospital due to a 10-day history of abdominal pain with elevated levels of serum amylase and lipase. Abdominal CT and ultrasound examinations were negative. In order to search for the cause, an 18F-FDG PET/CT whole body scan was suggested to an old woman revealing the presence of 18F-FDG accumulating nodule in small intestine.

Results: Surgical findings and pathologic results confirmed the diagnosis of small intestinal heterotopic pancreas with active chronic inflammation.

Conclusion: This uncommon case underscores the necessity of considering heterotopic pancreatitis in small intestine with focal 18F-FDG uptake as a possible differential diagnosis in intestinal tumor and tuberculosis.

aDepartment of Nuclear Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital

bDepartment of Nuclear Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.

Correspondence: Libo Chen, Department of Nuclear Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China (e-mail: libochen888@hotmail.com); Wenhui Xie, Department of Nuclear Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, P.R. China (e-mail: xknuclear@163.com).

Abbreviations: 18F-FDG PET = 18F-fluorodeoxyglucose positron-emission tomography, SUVmax = maximum standardized uptake value, HP = heterotopic pancreas.

WX and LC contributed equally to this study.

Funding: This work was partially sponsored by the National Natural Science Foundation of China (81271609) and Shanghai Rising-Star Program (12QH1401600).

The authors have no conflicts of interest to disclose.

This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. http://creativecommons.org/licenses/by/4.0

Received March 15, 2016

Received in revised form July 9, 2016

Accepted July 11, 2016

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1 Introduction

Heterotopic pancreas (HP) is a relatively uncommon congenital anomaly that is defined as pancreatic tissue without real anatomical or vascular connection to the pancreas.[1,2] Among all abdominal surgeries, the incidence of heterotopic pancreas ranges from 0.25% to 1.2%.[3,4] The most frequent locations are the duodenum (9%–36%), stomach (24%–38%), jejunum (0.5%–27%), and Meckel's diverticulum (2%–6.5%),[4,5] but it can also be found in the ileum, colon, gall bladder, umbilicus, fallopian tube, mediastinum, spleen, and liver.[3] This article reported a case of increased 18F-FDG uptake of heterotopic pancreatitis in the small intestine on 18F-FDG PET/CT.

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2 Case report

A 60-year-old woman was referred to our hospital due to a 10-day history of abdominal pain with elevated levels of serum amylase (431 U/L; reference range, 0–108 U/L) and lipase (627 U/L; reference range, 23–300 U/L). Abdominal CT and ultrasound examinations were negative. In order to search for the cause, an 18F-FDG PET/CT whole body scan was performed after the injection of 222 MBq (7 mCi) of 18F-FDG with a blood glucose level of 5.3 mmol/L. The maximum intensity projection PET image (Fig. 1A) revealed a focal increased 18F-FDG uptake lesion (arrow) and normal 18F-FDG uptake of the pancreas. Transverse CT (Fig. 1B), and corresponding PET (Fig. 1C) and fusion (Fig. 1D) images showed the lesion (thin arrow) with the SUVmax (maximum standardized uptake value) of 4.3 in the small intestine. Then, complete resection of the lesion was performed and abdominal pain disappeared. Low-magnification images (Fig. 2A and B, hematoxylin-eosin [HE] × 40) demonstrated the normal small intestine mucosa (thick arrow) and lobules of heterotopic pancreatic acini (thin arrows) in the submucosa. High-magnification image (Fig. 2C, HE × 200) of image F revealed destruction of the acini with infiltration of lymphocytes, indicating active chronic inflammation (arrow). The findings are consistent with a diagnosis of intestinal heterotypic pancreatitis.

Figure 1

Figure 1

Figure 2

Figure 2

A written informed consent for the case report was obtained from the patient. The consent procedure was approved by the Ethics Committee of Shanghai Jiao Tong University Affiliated Sixth People's Hospital.

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3 Discussion

HP can induce complications including inflammation, ulceration, chemical irritation, bleeding, obstruction, malignant transformation, jejunal intussusception, and ileus.[6–10] Surgical excision is the first and best choice of treatment because medical treatment is not effective.[6,10] However, the preoperative diagnosis of HP in the small intestine is difficult. Symptoms depend on the size of lesion and involvement of mucosa.[10] HP can frequently be mistaken as gastrointestinal stromal tumor or leiomyoma at endoscopy, ultrasonography, or CT scanning.[10,11] To our knowledge, HP with increased 18F-FDG accumulation has only been reported in 2 reports with the lesions in the stomach with the SUVmax of 4.0[12] and esophagus with the SUVmax of 10.0, which was concerned for a neoplasm before surgery.[13] However, the lesion with increased 18F-FDG accumulation in small intestine has not been reported before. As the inflammatory behavior of HP is similar to acute pancreatitis or focal exacerbation of chronic pancreatitis which occurs in the normal pancreatic gland,[14–18] increased 18F-FDG uptake in HP can be explained.[19–23] Notably, a high glucose metabolic activity in pancreatic tissues cannot distinguish neoplasm from inflammation.[24] The PET/CT finding with the noted 18F-FDG uptake in this case likely represented a localized inflammatory process, in accordance with the patient's symptomatology and the relatively low SUVmax of 4.3.

In conclusion, this case indicated that heterotopic pancreatitis in small intestine with focal 18F-FDG uptake should be considered when differing from leiomyoma,[25] lymphoma,[26] gastrointestinal stromal tumor,[27] and intestinal tuberculosis.[28]

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References

1. Cano DA, Hebrok M, Zenker M. Pancreatic development and disease. Gastroenterology 2007; 132:745–762.
2. Jiang LX, Xu J, Wang XW, et al Gastric outlet obstruction caused by heterotopic pancreas: a case report and a quick review. World J Gastroenterol 2008; 14:6757–6759.
3. Tanaka K, Tsunoda T, Eto T, et al Diagnosis and management of heterotopic pancreas. Int Surg 1993; 78:32–35.
4. Fukino N, Oida T, Mimatsu K, et al Adenocarcinoma arising from heterotopic pancreas at the third portion of the duodenum. World J Gastroenterol 2015; 21:4082–4088.
5. Thoeni RF, Gedgaudas RK. Ectopic pancreas: usual and unusual features. Gastrointest Radiol 1980; 5:37–42.
6. Okamoto H, Fujishima F, Ishida K, et al Intraductal papillary mucinous neoplasm originating from a jejunal heterotopic pancreas: report of a case. Surg Today 2014; 44:349–353.
7. Yang X, Guo K. Massive lower gastrointestinal bleeding from Meckel's diverticulum with heterotopic pancreas: case report and a brief review of the literature. JOP 2013; 14:269–272.
8. Gunjaca I, Mlinac-Lucijanic M, Pavlovic A, et al Inflammation of ectopic pancreatic tissue as unusual cause of duodenal perforation—a case report. Coll Antropol 2010; 34:1119–1122.
9. Hirasaki S, Kubo M, Inoue A, et al Jejunal small ectopic pancreas developing into jejunojejunal intussusception: a rare cause of ileus. World J Gastroenterol 2009; 15:3954–3956.
10. Kilius A, Samalavicius NE, Danys D, et al Asymptomatic heterotopic pancreas in Meckel's diverticulum: a case report and review of the literature. J Med Case Rep 2015; 9:108.
11. Kim JY, Lee JM, Kim KW, et al Ectopic pancreas: CT findings with emphasis on differentiation from small gastrointestinal stromal tumor and leiomyoma. Radiology 2009; 252:92–100.
12. Dong A, Wang Y, Dong H, et al Increased FDG uptake of heterotopic pancreatitis in the stomach. Clin Nucl Med 2013; 38:e438–e440.
13. Mack T, Lowry D, Carbone P, et al Multimodality imaging evaluation of an uncommon entity: esophageal heterotopic pancreas. Case Rep Radiol 2014; 2014:614347.
14. Rubesin SE, Furth EE, Birnbaum BA, et al Ectopic pancreas complicated by pancreatitis and pseudocyst formation mimicking jejunal diverticulitis. Br J Radiol 1997; 70:311–313.
15. Eisenberger CF, Kropp A, Langwieler TE, et al Heterotopic pancreatitis: gastric outlet obstruction due to an intramural pseudocyst and hamartoma. Z Gastroenterol 2002; 40:259–262.
16. Burke GW, Binder SC, Barron AM, et al Heterotopic pancreas: gastric outlet obstruction secondary to pancreatitis and pancreatic pseudocyst. Am J Gastroenterol 1989; 84:52–55.
17. Gananadha S, Hunt DR. A unique case of pancreatitis and retention cyst in esophageal heterotopic pancreas. Surg Laparosc Endosc Percutan Tech 2005; 15:345–347.
18. Almashat S, Sepehr A. Obstructive and inflammatory gastric heterotopic pancreatic tissue. Arch Iran Med 2011; 14:357–358.
19. Jeong Yoon S, Lee B, Park CH. Imaging diagnosis of post-ERCP focal pancreatitis mimicking pancreatic carcinoma by follow-up F-18 FDG PET/CT. Clin Nucl Med 2011; 36:70–72.
20. Shreve PD. Focal fluorine-18 fluorodeoxyglucose accumulation in inflammatory pancreatic disease. Eur J Nucl Med 1998; 25:259–264.
21. van Kouwen MC, Jansen JB, van Goor H, et al FDG-PET is able to detect pancreatic carcinoma in chronic pancreatitis. Eur J Nucl Med Mol Imaging 2005; 32:399–404.
22. Papos M, Takacs T, Tron L, et al The possible role of F-18 FDG positron emission tomography in the differential diagnosis of focal pancreatic lesions. Clin Nucl Med 2002; 27:197–201.
23. Yokoyama Y, Nagino M, Hiromatsu T, et al Intense PET signal in the degenerative necrosis superimposed on chronic pancreatitis. Pancreas 2005; 31:192–194.
24. Zhuang H, Pourdehnad M, Lambright ES, et al Dual time point 18F-FDG PET imaging for differentiating malignant from inflammatory processes. J Nucl Med 2001; 42:1412–1417.
25. Maeda M, Kanke K, Sasai T, et al [(1)(8)F-fluorodeoxyglucose PET/CT and small bowel endoscopy in a patient with small bowel leiomyoma]. Nihon Shokakibyo Gakkai Zasshi 2012; 109:1561–1566.
26. Zhu L, Wu G, Ghimire P, et al CT features of peripheral T-cell lymphoma in the gastrointestinal tract in Chinese population and literature review. J Med Imaging Radiat Oncol 2012; 56:143–150.
27. Misawa S, Takeda M, Sakamoto H, et al Spontaneous rupture of a giant gastrointestinal stromal tumor of the jejunum: a case report and literature review. World J Surg Oncol 2014; 12:153.
28. Zhao XS, Wang ZT, Wu ZY, et al Differentiation of Crohn's disease from intestinal tuberculosis by clinical and CT enterographic models. Inflamm Bowel Dis 2014; 20:916–925.
Keywords:

18F-FDG PET/CT; case report; heterotopic pancreas; pancreatitis; small intestine

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