Ann Hepatobiliary Pancreat Surg.  2019 Aug;23(3):300-304. 10.14701/ahbps.2019.23.3.300.

Circumportal pancreas: A report of two cases

• Kabir T
• Xuan ZT
• Chung AY

• KMID: 2456032
• DOI: http://doi.org/10.14701/ahbps.2019.23.3.300

Abstract

Circumportal pancreas (CP) is an unusual pancreatic anomaly occurring in 1.1 to 2.5% of individuals, where there is abnormal fusion of the uncinate process to the main pancreatic body occurring to the left of the portal vein-superior mesenteric vein (PV-SMV) junction. Since it was first described in 1987, there have only been a few reports documented in the literature. We recently encountered 2 such cases. Patient 1 was an 81-year-old man who presented with weight loss. Computed tomography (CT) scan revealed an atrophic pancreas with dilated pancreatic duct and a nodule at the head of pancreas, suspicious for a main-duct intraductal papillary mucinous neoplasm (IPMN) with malignant change. During surgery, we discovered that the uncinate process of the pancreas was completely wrapped around the SMV and fused with the main body, resulting in encasement of the PV-SMV junction. The patient also had a replaced right hepatic artery (RHA). Patient 2 was a 76-year-old man who complained of several weeks of abdominal discomfort. A CT scan showed a dilated common bile duct with a distal mass, worrisome for distal cholangiocarcinoma. Intra-operatively, he was similarly found to have union of the uncinate process of the pancreas with the main body occurring to the left of the PV-SMV confluence, with bilateral anomalous hepatic arteries. We present a brief review of the literature surrounding this condition. Although CP is usually asymptomatic, failure to recognize it may lead to serious consequences.

Keyword

Circumportal; Annular; Pancreas; Portal

MeSH Terms

Aged
Aged, 80 and over
Cholangiocarcinoma
Common Bile Duct
Head
Hepatic Artery
Humans
Mesenteric Veins
Mucins
Pancreas*
Pancreatic Ducts
Tomography, X-Ray Computed
Weight Loss
Mucins

Figure

• 

  Fig. 1 Intra-operative photograph of patient 1 showing the uncinate process of the pancreas fused with the main body, encircling the superior mesenteric vein-portal vein junction (with blue vessel loop).

• 

  Fig. 2 Resected specimen of patient 1 with staple line indicating where the fused uncinate process was divided. The surgical ruler delineates the path of the superior mesenteric vein and portal vein.

• 

  Fig. 3 Computed tomography scan of patient 1 showing the uncinate process fused to the main body (white arrow) and dilated anteportal and retroportal pancreatic ducts.

• 

  Fig. 4 Computed tomography scan of patient 2 showing fused uncinate process fused to the main body, to the left of superior mesenteric vein-portal vein confluence (white arrow).

• 

  Fig. 5 Computed tomography scan of patient 2 showing fused uncinate process fused to main body, to the left of the superior mesenteric vein-portal vein confluence (white arrow).

• 

  Fig. 6 Computed tomography scan of patient 2 showing fused uncinate process fused to the main body, to the left of superior mesenteric vein-portal vein confluence (white arrow).

Reference

1. Harnoss JM, Harnoss JC, Diener MK, Contin P, Ulrich AB, Büchler MW, et al. Portal annular pancreas: a systematic review of a clinical challenge. Pancreas. 2014; 43:981–986. PMID: 25207658.

2. Ishigami K, Tajima T, Nishie A, Asayama Y, Kakihara D, Nakayama T, et al. The prevalence of circumportal pancreas as shown by multidetector-row computed tomography. Insights Imaging. 2011; 2:409–414. PMID: 22347962.

3. Sugiura Y, Shima S, Yonekawa H, Yoshizumi Y, Ohtsuka H, Ogata T. The hypertrophic uncinate process of the pancreas wrapping the superior mesenteric vein and artery--a case report. Jpn J Surg. 1987; 17:182–185. PMID: 3626212.

4. Joseph P, Raju RS, Vyas FL, Eapen A, Sitaram V. Portal annular pancreas. A rare variant and a new classification. JOP. 2010; 11:453–455. PMID: 20818114.

5. Karasaki H, Mizukami Y, Ishizaki A, Goto J, Yoshikawa D, Kino S, et al. Portal annular pancreas, a notable pancreatic malformation: frequency, morphology, and implications for pancreatic surgery. Surgery. 2009; 146:515–518. PMID: 19715809.

6. Marjanovic G, Obermaier R, Benz S, Bley T, Juettner E, Hopt UT, et al. Complete pancreatic encasement of the portal vein--surgical implications of an extremely rare anomaly. Langenbecks Arch Surg. 2007; 392:489–491. PMID: 17221270.

7. Leyendecker JR, Baginski SG. Complete pancreatic encasement of the portal vein (circumportal pancreas): imaging findings and implications of a rare pancreatic anomaly. J Comput Assist Tomogr. 2008; 32:61–64. PMID: 18303289.

8. Yamazaki S, Kaneko T, Fujinaga Y, Kadoya M, Ochi Y, Sasaki K. CT and MRI features of unclassifiable pancreatic anomaly with superior mesenteric vein running through the pancreatic parenchyma. Eur J Radiol Extra. 2005; 54:59–61.

9. Song SY, Oh JY, Kim Y, Cho OK, Koh BH. Complete pancreatic encasement of portal vein: circumportal pancreas. Eur Radiol Suppl. 2008; 18:350.

10. Tappouni R, Perumpillichira J, Sekala M, Hosseinzadeh K, Clark C, Leyendecker J. Circumportal pancreas: imaging findings in 40 patients. Abdom Imaging. 2015; 40:521–530. PMID: 25248793.

11. Ohtsuka T, Mori Y, Ishigami K, Fujimoto T, Miyasaka Y, Nakata K, et al. Clinical significance of circumportal pancreas, a rare congenital anomaly, in pancreatectomy. Am J Surg. 2017; 214:267–272. PMID: 27871680.

12. Kiuchi R, Mizuno T, Okamura Y, Sugiura T, Kanemoto H, Uesaka K. Circumportal pancreas - a hazardous anomaly in pancreatic surgery. HPB (Oxford). 2018; 20:385–391. PMID: 29198420.

13. Yilmaz E, Celik A. Circumportal pancreas: prevalence, subtypes and vascular variations of 55 patients. Surg Radiol Anat. 2018; 40:407–413. PMID: 29380102.

14. Pardiwala KH, Maker AV. Operative management of portal annular pancreas during pancreaticoduodenectomy. Surgery. 2016; 159:972–974. PMID: 26144878.

15. Lath CO, Agrawal DS, Timins ME, Wein MM. Portal annular pancreas: the pancreatic duct ring sign on MRCP. Radiol Case Rep. 2015; 10:42–45. PMID: 26649117.

16. Connelly TM, Sakala M, Tappouni R. Circumportal pancreas: a review of the literature and image findings. Surg Radiol Anat. 2015; 37:431–437. PMID: 25626884.

17. Luu AM, Braumann C, Herzog T, Janot M, Uhl W, Chromik AM. Circumportal pancreas-a must know pancreatic anomaly for the pancreatic surgeon. J Gastrointest Surg. 2017; 21:344–351. PMID: 27826941.

18. Jang JY, Chung YE, Kang CM, Choi SH, Hwang HK, Lee WJ. Two cases of portal annular pancreas. Korean J Gastroenterol. 2012; 60:52–55. PMID: 22832801.

19. Hashimoto Y, Ross AS, Traverso LW. Circumportal pancreas with retroportal main pancreatic duct. Pancreas. 2009; 38:713–715. PMID: 19629006.

20. Muto J, Mano Y, Harada N, Uchiyama H, Yoshizumi T, Taketomi A, et al. Additional resection of the pancreas body prevents postoperative pancreas fistula in patients with portal annular pancreas who undergo pancreaticoduodenectomy. Case Rep Gastroenterol. 2012; 6:131–134. PMID: 22532811.