Pancreatic Pseudocysts Workup
- Author: Louis R Lambiase, MD, MHA; Chief Editor: BS Anand, MD more...
Serum tests have limited use. Amylase and lipase levels are often elevated but may be within reference ranges. Bilirubin and liver function test (LFT) findings may be elevated if the biliary tree is involved.
Analysis of the cyst fluid may help differentiate pseudocysts from tumors. An attempt should be made to exclude tumors in any patient who does not have a clear history of pancreatitis. Note the following:
- Carcinoembryonic antigen (CEA) and carcinoembryonic antigen-125 (CEA-125) tumor marker levels are low in pseudocysts and elevated in tumors.
- Fluid viscosity is low in pseudocysts and elevated in tumors.
- Amylase levels are usually high in pseudocysts and low in tumors.
- Cytology is occasionally helpful in diagnosing tumors, but a negative result does not exclude tumors.
- A CEA level of greater than 400 ng/mL within the cyst fluid strongly suggests malignancy.
Abdominal ultrasonography may be used to visualize cystic fluid collections in and around the pancreas. However, the technique is limited by the operator’s skill, the patient's habitus, and any overlying bowel gas. As such, ultrasonography is not the study of choice to establish a diagnosis.
Endoscopic ultrasonography (EUS) is not necessary to establish a diagnosis but is very important in planning therapy, particularly if endoscopic drainage is contemplated.
A gastric wall with a thickness greater than 1 cm next to the cyst tends to predict a poor outcome with endoscopic drainage.
EUS may also be helpful in detecting small portal collaterals from otherwise undetected portal hypertension that may increase bleeding risks with transmural drainage.
Transmural drainage may be performed only when the symptomatic pseudocyst is positioned next to the gut wall. See the image below.
Computed Tomography Scanning
Abdominal computed tomography (CT) scanning is the imaging criterion standard for pancreatic pseudocysts. It has a sensitivity of 90-100% and is not operator dependent. Note the following:
- The usual finding on CT scan is a large cyst cavity in and around the pancreas.
- Multiple cysts may be present.
- The pancreas may appear irregular or have calcifications.
- Pseudoaneurysms of the splenic artery, bleeding into a pseudocyst, biliary and enteric obstruction, and other complications may be noted on CT scan.
- The CT scan provides a very good appreciation of the wall thickness of the pseudocyst, which is useful in planning therapy.
Endoscopic Retrograde Cholangiopancreatography
Endoscopic retrograde cholangiopancreatography (ERCP) is not necessary in diagnosing pseudocysts; however, it is useful in planning drainage strategy.
A study by Neil et al investigated the use of ERCP and the treatment of pseudocysts and acute pancreatitis and reported that a change in management occurred 35% of the time after the ERCP findings in pseudocysts were evaluated. Therefore, many authors recommend performing an ERCP before contemplated drainage procedures.
Magnetic Resonance Imaging
Magneic resonance imaging (MRI) is not necessary to establish a diagnosis of pseudocysts; however, it is useful in detecting a solid component in the cyst and in differentiating between organized necrosis and a pseudocyst.
A solid component makes catheter drainage difficult; therefore, in the setting of acute necrotizing pancreatitis with resultant pseudocyst, an MRI may be very important before a planned catheter drainage procedure.
Histologic findings vary with age because older cysts have thicker walls with more collagen. The etiology of the cyst does not change the histology. Note the following zone features:
- Zone 1 - Hemosiderin pigment and loose connective tissue
- Zone 2 - Inflammatory cells and capillary-rich fibrous tissue
- Zone 3 - Hyalinized acellular connective tissue
- Zone 4 - Capillary-rich fibrous stroma
Brun A, Agarwal N, Pitchumoni CS. Fluid collections in and around the pancreas in acute pancreatitis. J Clin Gastroenterol. 2011 Aug. 45(7):614-25. [Medline].
Vege SS, Ziring B, Jain R, Moayyedi P. American Gastroenterological Association Institute guideline on the diagnosis and management of asymptomatic neoplastic pancreatic cysts. Gastroenterology. 2015 Apr. 148(4):819-22. [Medline].
Bhasin DK, Rana SS, Sharma V, Rao C, Gupta V, Gupta R, et al. Non-surgical management of pancreatic pseudocysts associated with arterial pseudoaneurysm. Pancreatology. 2013 May-Jun. 13(3):250-3. [Medline].
Zheng M, Qin M. Endoscopic ultrasound guided transgastric stenting for the treatment of traumatic pancreatic pseudocyst. Hepatogastroenterology. 2011 Jul-Aug. 58(109):1106-9. [Medline].
Weckman L, Kylanpaa ML, Puolakkainen P, Halttunen J. Endoscopic treatment of pancreatic pseudocysts. Surg Endosc. 2006 Apr. 20(4):603-7. Epub 2006 Jan 19. [Medline].
FDA news release. FDA allows marketing of new stent for treating pseudocysts of the pancreas. December 18, 2013. Available at http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm379195.htm. Accessed: January 7, 2014.
Varadarajulu S, Bang JY, Sutton BS, Trevino JM, Christein JD, Wilcox CM. Equal Efficacy of Endoscopic and Surgical Cystogastrostomy for Pancreatic Pseudocyst Drainage in a Randomized Trial. Gastroenterology. 2013 May 31. [Medline].
Aljarabah M, Ammori BJ. Laparoscopic and endoscopic approaches for drainage of pancreatic pseudocysts: a systematic review of published series. Surg Endosc. 2007 Nov. 21(11):1936-44. [Medline].
Oida T, Mimatsu K, Kano H, Kawasaki A, Kuboi Y, Fukino N, et al. Laparoscopic Cystogastrostomy via the Posterior Approach for Pancreatic Pseudocyst Drainage. Hepatogastroenterology. 2011 Nov 14. 58(110-111):1771-1775. [Medline].
Beckingham IJ, Krige JE, Bornman PC, Terblanche J. Long term outcome of endoscopic drainage of pancreatic pseudocysts. Am J Gastroenterol. 1999 Jan. 94(1):71-4. [Medline].
Binmoeller KF, Seifert H, Walter A, Soehendra N. Transpapillary and transmural drainage of pancreatic pseudocysts. Gastrointest Endosc. 1995 Sep. 42(3):219-24. [Medline].
Criado E, De Stefano AA, Weiner TM, Jaques PF. Long term results of percutaneous catheter drainage of pancreatic pseudocysts. Surg Gynecol Obstet. 1992 Oct. 175(4):293-8. [Medline].
D'Agostino HB, vanSonnenberg E, Sanchez RB, Goodacre BW, Villaveiran RG, Lyche K. Treatment of pancreatic pseudocysts with percutaneous drainage and octreotide. Work in progress. Radiology. 1993 Jun. 187(3):685-8. [Medline].
El Hamel A, Parc R, Adda G, Bouteloup PY, Huguet C, Malafosse M. Bleeding pseudocysts and pseudoaneurysms in chronic pancreatitis. Br J Surg. 1991 Sep. 78(9):1059-63. [Medline].
Gershoni-Baruch R, Mandel H, Bar El H, Bar-Nizan N, Borochowitz Z, Dar H. Interstitial deletion (6)q13q15. Am J Med Genet. 1996 Apr 24. 62(4):345-7. [Medline].
Heider R, Meyer AA, Galanko JA, Behrns KE. Percutaneous drainage of pancreatic pseudocysts is associated with a higher failure rate than surgical treatment in unselected patients. Ann Surg. 1999 Jun. 229(6):781-7; discussion 787-9. [Medline].
Howell DA, Elton E, Parsons WG. Endoscopic management of pseudocysts of the pancreas. Gastrointest Endosc Clin N Am. 1998 Jan. 8(1):143-62. [Medline].
Lewandrowski KB, Southern JF, Pins MR, Compton CC, Warshaw AL. Cyst fluid analysis in the differential diagnosis of pancreatic cysts. A comparison of pseudocysts, serous cystadenomas, mucinous cystic neoplasms, and mucinous cystadenocarcinoma. Ann Surg. 1993 Jan. 217(1):41-7. [Medline].
Morton JM, Brown A, Galanko JA, Norton JA, Grimm IS, Behrns KE. A national comparison of surgical versus percutaneous drainage of pancreatic pseudocysts: 1997-2001. J Gastrointest Surg. 2005 Jan. 9(1):15-20; discussion 20-1. [Medline].
Nealon WH, Walser E. Surgical management of complications associated with percutaneous and/or endoscopic management of pseudocyst of the pancreas. Ann Surg. 2005 Jun. 241(6):948-57; discussion 957-60. [Medline].
Nguyen BL, Thompson JS, Edney JA, Bragg LE, Rikkers LF. Influence of the etiology of pancreatitis on the natural history of pancreatic pseudocysts. Am J Surg. 1991 Dec. 162(6):527-30; discussion 531. [Medline].
Pitchumoni CS, Agarwal N. Pancreatic pseudocysts. When and how should drainage be performed?. Gastroenterol Clin North Am. 1999 Sep. 28(3):615-39. [Medline].
Sahani DV, Kadavigere R, Saokar A, Fernandez-del Castillo C, Brugge WR, Hahn PF. Cystic pancreatic lesions: a simple imaging-based classification system for guiding management. Radiographics. 2005 Nov-Dec. 25(6):1471-84. [Medline].
Soliani P, Franzini C, Ziegler S, Del Rio P, Dell'Abate P, Piccolo D, et al. Pancreatic pseudocysts following acute pancreatitis: risk factors influencing therapeutic outcomes. JOP. 2004 Sep. 5(5):338-47. [Medline].
Vitas GJ, Sarr MG. Selected management of pancreatic pseudocysts: operative versus expectant management. Surgery. 1992 Feb. 111(2):123-30. [Medline].
Warshaw AL, Compton CC, Lewandrowski K, Cardenosa G, Mueller PR. Cystic tumors of the pancreas. New clinical, radiologic, and pathologic observations in 67 patients. Ann Surg. 1990 Oct. 212(4):432-43; discussion 444-5. [Medline].
Warshaw AL, Rutledge PL. Cystic tumors mistaken for pancreatic pseudocysts. Ann Surg. 1987 Apr. 205(4):393-8. [Medline].
Yeo CJ, Bastidas JA, Lynch-Nyhan A, Fishman EK, Zinner MJ, Cameron JL. The natural history of pancreatic pseudocysts documented by computed tomography. Surg Gynecol Obstet. 1990 May. 170(5):411-7. [Medline].