Most patients who are diagnosed with PC do not present any symptoms at all. Cysts are incidental findings during unrelated magnetic resonance imaging or computed tomography scans. If patients develop symptoms, these might be related to a space-occupying cyst interfering with the correct functioning of organs in close proximity or intrinsic pancreatic disorders.

Space-occupying cysts, particularly if located in the head of the pancreas, may compress the bile duct or the major duodenal papilla and thus trigger post-hepatic jaundice. If the duodenum itself is affected, food passage from the stomach into this part of the small intestine may be delayed. Loss of appetite, nausea, vomiting and bloating may then be experienced. If this condition persists for longer periods of time, patients may lose weight.

Abdominal pain that radiates towards the back may be caused by PC. It may also indicate pancreatitis.

• Collapse

  After cystogastrostomy stent placement, the patient developed dramatic symptomatic improvement of gastric outlet obstructive symptoms, although subsequent imaging did not reveal complete collapse of the cystic structure. [ncbi.nlm.nih.gov]

• Abdominal Mass

  Congenital pancreatic cysts, particularly solitary cysts, are rare causes of abdominal masses in newborns. The etiology of these cysts is unknown and they can vary in location within the pancreas. [ncbi.nlm.nih.gov]

  Some of the more common signs and symptoms include : Abdominal pain Back pain Abdominal mass with/without tenderness Nausea and vomiting Additional symptoms may depend on the compression of surrounding structures by larger cysts. [healthhype.com]

  They can grow to be quite large and can even present as a palpable abdominal mass. On imaging, these cysts demonstrate multiple small compartments and are often describe as having a ‘honeycomb’ appearance. [winthrop.org]

  They can grow to be quite large, and some patients will have an abdominal mass easily observed upon physical examination. CT scan will reveal a cystic mass with a central scar and often with calcification. [columbiasurgery.org]

  Javle et al. [23] found that palpable abdominal mass on presentation was significantly more in the malignant group (4/17 patients) than in the benign group (0/18 patients). [dx.doi.org]

• Chronic Abdominal Pain

  Both patients were women (ages 37 and 42) with a history of chronic abdominal pain and pancreatitis. Radiologic imaging showed cystic lesions in the pancreatic tail. ERCP demonstrated main pancreatic duct communication. [ncbi.nlm.nih.gov]

  abdominal pain, and recurrent pancreatitis (if obstruction is present), along with nonspecific symptoms of back pain, weight loss, anorexia, nausea, and vomiting. [8] Imaging Pancreatic cysts can be assessed with multiple imaging modalities, including [carcinogenesis.com]

• Heart Murmur

  The patient, a previously healthy 16-year-old girl, was found to have a cystic lesion in the anterior mediastinum during investigation of an asymptomatic heart murmur. The lesion measured 12 cm in maximal diameter and contained dark, turbid fluid. [ncbi.nlm.nih.gov]

• Abnormal Behavior

  RESULTS: Among 1466 pancreatic cyst fluids tested, about 10% to 15% of samples presented abnormal behaviors: (i) radioactivity measured after immunoradiometric assay much lower than the blank of the assay and (ii) increasing dilution of the fluids leading [ncbi.nlm.nih.gov]

Cysts which are not detected incidentally during abdominal scans can be identified using imaging techniques to identify the cause of abdominal pain, post-hepatic jaundice or delayed stomach emptying. Magnetic resonance imaging, particularly magnetic resonance cholangiopancreatography, and computed tomography or contrast-enhanced computed tomography, may be employed to assess the pancreas and bile ducts. Contrast-enhanced computed tomography is the ideal method for radiologic diagnosis. Transabdominal or endoscopic ultrasonography may provide an alternative mode for diagnosis but may be less sensitive. These techniques allow one to determine if adjacent tissues or blood vessels are compromised or pose a risk if surgical interventions need to be carried out.

As the aforementioned diagnostic measures are not invasive, they do not allow extraction of biopsy samples and therapeutic interventions. In contrast, minimally invasive endoscopic retrograde cholangiopancreatography combined with diagnostic imaging enables the internist to do both. However, general anesthesia is required for this procedure and may be risky in certain patients.

The overall condition of the patient, size, and location of the PC, results of laboratory analysis of blood samples and histopathologic examination of biopsy samples will determine the choice of treatment.

• Pneumoperitoneum

  Specifically, complications recorded were infection (6%), perforation and acute abdomen necessitating surgical intervention (4.6%), pneumoperitoneum that was managed nonoperatively (3%), upper gastrointestinal bleed in the knife puncture site that resolved [ncbi.nlm.nih.gov]

If abdominal scans confirm the presence of an asymptomatic, innocuous pseudocyst unlikely to compromise adjacent structures anytime soon, monitoring may be all the treatment needed. This also applies to patients diagnosed with serous cystadenoma, which is a benign neoplasm that rarely undergoes malignant transformation.

PC which causes problems merely due to its size does not require excision and can be drained via an endoscopic procedure. There are two different options, both considered superior to the open surgical approach [5]. On the one hand, endoscopic retrograde cholangiopancreatography, as mentioned in the previous paragraph, may be utilized to access and drain PC that communicates with the main pancreatic duct. The success rate has been reported to be about 80% with little more than 10% of patients treated this way suffering from recurrences. About the same number of patients may suffer complications, most commonly pancreatitis. Pancreatitis increases the risk for relapses [6]. On the other hand, PC may be accessed transmurally. In order to do so, a small cut through the gastric or intestinal wall is required. It is usually set directly above the cyst. A stent may then be inserted that connects the PC and the gastrointestinal tract. The cyst will drain slowly and its walls will adhere to each other, which prevents refilling. Such a stent needs to be removed in a second endoscopic intervention. Success and recurrence rates are similar to the transpapillary approach, but the complication rate is higher and has been estimated to 20%. The most common complications are hemorrhages [7]. Success, relapse, and complication rates have been confirmed by other studies too [8] [9]. Laparoscopy may be a valuable alternative to the endoscopic approach [9] [10].

For pseudocysts and serous cystadenoma, surgical resection is only required if they are causing symptoms. For any other type of PC, excision is generally recommended due to the risk of malignant transformation.

Prognosis of PC depends on the precise type of cyst, on possible relations to neoplasms , whether benign or malignancy at the time of diagnosis. The vast majority of PC correspond to pseudocysts that have a very good prognosis unless the overall condition of the patient does not allow adequate treatment in case this should be necessary.

If large parts of the pancreas have to be removed, symptoms of exocrine and endocrine pancreatic insufficiency might develop. Obviously, this also applies to patients that undergo total pancreatectomy.

Pseudocysts are often related to abdominal trauma, particularly to trauma sustained in motor vehicle accidents, or pancreatitis. Of note, traumatic injury of the pancreas may cause the organ's digestive enzymes to damage the pancreatic parenchyma and trigger pancreatitis. Thus, both conditions are often diagnosed simultaneously.

Congenital cysts are of unknown etiology but have been associated with genetic disorders such as von Hippel-Lindau disease.

Any pathological condition causing an obstruction of pancreatic ducts may provoke the development of retention cysts. As has been mentioned above, pancreoliths may account for this type of PC. Neoplasms that may or may not grow within the pancreas are other potential causes of retention cysts. Although PC due to intraductal papillary mucinous neoplasms are listed as a separate class of PC, the pathogenetic mechanism is largely the same.

Precise causes of pancreatic neoplasms associated with PC are not known.

Reported prevalence rates of all types of PC have been increasing recently. Particularly small PC that may have escaped notice in standard radiographic images are more often detected during magnetic resonance imaging or computed tomography scans.

In one study, almost 3,000 scans have been retrospectively analyzed for the presence of PC and such were found in 2.6% of all patients [3]. Similar results have been published elsewhere [4]. The vast majority of these patients only displayed one single cyst. PC had an average diameter of 9 mm, whereby the smallest cysts measured only 2 mm and the largest 38 mm.

Prevalence of PC increases with age. In fact, the aforementioned study did not report any such incidental finding in patients aged less than 40 years. The subgroup of patients aged 80 years and older, however, showed prevalence rates of 8.7%.

Gender distribution may not be equal for all kinds of PC. Mucinous cystic neoplasms, for instance, are most frequently detected in women.

Similar to other organs that release fluids or that concentrate liquids in any form, e.g. liver, kidneys, and ovaries, the anatomic structure of the pancreas makes it prone to the development of cysts. Here, digestive enzymes flow via small intrapancreatic ducts into the main pancreatic duct and subsequently into the duodenum. The pancreas provides proteases like trypsinogen and chymotrypsinogen, amylase and lipase. Although essential for digestion, contact of these active enzymes with the pancreatic parenchyma is detrimental. Premature activation of pancreatic enzymes may occur after abdominal trauma, provoke pancreatitis, tissue digestion and formation of pseudocysts. Under physiological conditions, enzyme activation does not take place until the duodenum is reached.

Pseudocysts and most other PC are of benign nature. However, the possibility of malignant transformation exists. With regards to intraductal papillary mucinous neoplasms, it has been speculated that those cysts located in the main pancreatic duct and those detected in the elderly are more likely to become malignant. Similarly, subdivided cysts due to mucinous cystic neoplasms have a higher probability to progress from precancerous to cancerous lesions.

Although there is no absolute way to avoid development of PC, the majority of PC are pseudocysts resulting from abdominal trauma and pancreatitis. Trauma may be prevented by choosing a safe lifestyle as pancreatitis is often related to alcohol abuse. Thus, alcohol should be consumed in moderation or not at all.

The term pancreatic cyst (PC) refers to any fluid-filled pouch within the pancreas. They are often detected incidentally when patients undergo magnetic resonance imaging (MRI) or computed tomography (CT) scans of the abdomen scans are usually performed for unrelated reasons. Some PC may even be visible on standard radiologic images.

Although the majority of PC are of benign nature, in some cases they may have precancerous tissue alterations or be directly related to the presence of malignancies [1]. Diagnostic measures need to be taken to distinguish these types of PC and to initiate surgical treatment if any relation to cancer is suspected. Thus, if PC are detected in diagnostic images, biopsy samples can be obtained endoscopically for analysis. Benign PCs may also require surgical intervention if their location or size impairs the correct functioning of adjacent organs, e.g., the hepatobiliary or gastrointestinal tract. Symptoms triggered by PC may be nausea, vomiting, bloating, diarrhea and abdominal pain. Symptomatic cysts can be drained or resected but PC suspicious for cancer should be removed.

According to the aforementioned characteristics, a wide variety of cysts can be distinguished. Among the more common types of PC are the following:

• Pseudocysts: These are by far the most common PCs. They are not lined with epithelium as they result from local tissue damage after trauma and/or inflammation. Indeed, if detected, anamnesis frequently reveals abdominal trauma or pancreatitis several weeks ago. Instead of epithelium, fibrous scar tissue lines these sacs of fluid rich in pancreatic enzymes [2].
• Congenital cysts. They result from developmental defects and non-physiologic dilation of intrapancreatic spaces. They may or may not be connected to pancreatic ducts.
• Retention cysts. These PC are not congenital but result from obstruction and secondary dilation of pancreatic ducts. For instance, pancreatic calculi may account for the development of these cysts.
• Intraductal papillary mucinous neoplasm. Albeit this term suggests a cancerous process, this type of PC is related with precancerous alterations that take place within the pancreatic ducts. They produce large amounts of mucinous substances that obstruct the aforementioned ducts and provoke the development of retention cysts.
• Mucinous cystic neoplasm. Similar to intraductal papillary mucinous neoplasm. These are precancerous alterations. They do, however, develop in the pancreatic parenchyma.
• Serous cystadenoma. This type of PC is characterized by a thick, fibrous wall that surrounds considerable amounts of clear fluid. Serous cystadenoma is a benign neoplasm but may cause symptoms due to its size.

The pancreas is an organ located in the upper part of the abdomen; it produces a variety of digestive enzymes that are transported via intra-pancreatic ducts into one main pancreatic duct that, in turn, reaches the duodenum. Pancreatic enzymes are necessary to digest all main nutrients, i.e., carbohydrates, proteins and lipids. Under certain pathologic conditions, the aforementioned ducts may dilate or fluid-filled spaces may form in other parts of the pancreas. Such events create a pancreatic cyst (PC).

Causes

PC may have multiple causes. Some may be present at birth and result from developmental disturbances. However, the most common type of PC forms after trauma, particularly motor vehicle accidents, or inflammation and directly follows tissue damage. This type of PC is called pseudocyst. Similar to bile ducts and the urinary system, calculi may form inside pancreatic ducts, obstruct them and provoke retention cysts. There is also a wide variety of precancerous and cancerous PC. It may not always be easy to distinguish one from another and precancerous cells may eventually undergo malignant transformation.

Symptoms

Most PC are incidental findings detected during magnetic resonance imaging or computed tomography scans carried out for unrelated issues.

In some cases, PC may cause abdominal pain that radiates towards the back. If PC are located in the head of the pancreas and thus in close proximity to the bile duct and the duodenum, they may compress these structures. That would cause jaundice or nausea and vomiting respectively.

Diagnosis

As has been mentioned above, PC are usually detected with imaging techniques. If a patient presents with any of the aforementioned symptoms, these same methods may be applied to identify their trigger and possibly diagnose PC. Endoscopic procedures may be required to obtain a biopsy. Such a tissue sample will then be analyzed histopathologically and may reveal important information as to the nature of the cyst.

Treatment

Treatment depends on location and size of the PC, whether symptomatic or asymptomatic and finally on its nature. Pseudocysts and serous cystadenoma, a benign neoplasm, may just be monitored if they do not cause any symptoms. Otherwise, a minimally invasive surgery may be required to drain those cysts.

Any PC that may potentially undergo malignant transformation should be resected.

1. Allen PJ, D'Angelica M, Gonen M, et al. A selective approach to the resection of cystic lesions of the pancreas: results from 539 consecutive patients. Ann Surg. 2006; 244(4):572-582.
2. Brun A, Agarwal N, Pitchumoni CS. Fluid collections in and around the pancreas in acute pancreatitis. J Clin Gastroenterol. 2011; 45(7):614-625.
3. Laffan TA, Horton KM, Klein AP, et al. Prevalence of unsuspected pancreatic cysts on MDCT. AJR Am J Roentgenol. 2008; 191(3):802-807.
4. de Jong K, Nio CY, Hermans JJ, et al. High prevalence of pancreatic cysts detected by screening magnetic resonance imaging examinations. Clin Gastroenterol Hepatol. 2010; 8(9):806-811.
5. 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; 145(3):583-590 e581.
6. Bhasin DK, Rana SS, Sharma V, et al. Non-surgical management of pancreatic pseudocysts associated with arterial pseudoaneurysm. Pancreatology. 2013; 13(3):250-253.
7. Zheng M, Qin M. Endoscopic ultrasound guided transgastric stenting for the treatment of traumatic pancreatic pseudocyst. Hepatogastroenterology. 2011; 58(109):1106-1109.
8. Weckman L, Kylanpaa ML, Puolakkainen P, Halttunen J. Endoscopic treatment of pancreatic pseudocysts. Surg Endosc. 2006; 20(4):603-607.
9. Aljarabah M, Ammori BJ. Laparoscopic and endoscopic approaches for drainage of pancreatic pseudocysts: a systematic review of published series. Surg Endosc. 2007; 21(11):1936-1944.
10. Oida T, Mimatsu K, Kano H, et al. Laparoscopic cystogastrostomy via the posterior approach for pancreatic pseudocyst drainage. Hepatogastroenterology. 2011; 58(110-111):1771-1775.