Pancreatic pseudocyst is a collection of pancreatic secretions encapsulated by granulation and fibrous tissue and occurs primarily in the setting of either acute and chronic pancreatitis. Clinical course may be asymptomatic, while abdominal pain, vomiting and other gastrointestinal symptoms are reported. The diagnosis is made by ultrasound and other imaging studies, while treatment can range from observation and conservative treatment to surgery.
The clinical presentation of patients with pancreatic pseudocysts may vary significantly. The disease may have an asymptomatic course, in which little or no symptoms may be present. In most cases, nonspecific complaints of abdominal pain, nausea, bloating and vomiting are reported, which cannot immediately point to a pancreatic pseudocyst as the cause of symptoms. Pallor and weakness may be present in the case of bleeding and consequent anemia, while jaundice and fever may also be present . In some cases, when larger cysts are present, an abdominal mass may be palpated during the physical examination, with a generally tender abdomen, especially in the cases with bleeding. In more severe cases, when rupture of pseudocysts occurs, hypotension and shock may be present, which necessitates rapid treatment.
The diagnostic workup of pancreatic pseudocysts includes a detailed approach to the patient. Initial patient history may provide important clues, such as a history of pancreatitis and progression of symptoms prior to admission. In all patients with nonspecific abdominal symptoms, ultrasonography can be very useful in differentiating pancreatic lesions from other processes in the abdomen. Cystic formations can be detected with ultrasonography which has very high specificity, low cost and easy availability making it an efficient method for initial diagnosis. However, a definite diagnosis can be made by either CT or MRI, which can provide a better view into pancreatic tissue . These imaging techniques can reveal the exact size and location of cysts, and can also establish whether more than one cyst is present. Endoscopic retrograde cholangiopancreatography (ERCP) is a useful, but invasive technique which is used for evaluation of surgical treatment. In some cases, a histological confirmation is necessary to differentiate pseudocysts from other cystic lesions that proliferate such as neoplasia. This can be achieved through endoscopic ultrasound and aspiration biopsy .
There are several treatment modalities that can be used for managing pancreatic pseudocysts. For patients with a mild or asymptomatic clinical course, treatment may not be necessary, as pseudocysts tend to resolve spontaneously within several weeks. However, in patients with development of complications, progressively enlarging pseudocysts, and with poor general condition, one of several treatment procedures may be indicated:
The prognosis of patients with pancreatic pseudocysts depends on various factors, as the cause and course of the disease have a significant impact on the outcome. The presence of asymptomatic or mild form of the disease is known to result in spontaneous resolution of pseudocysts. . but several complications may arise. They include abscess formation and sepsis, while rupture with or without hemorrhage is a particularly troubling issue, since it may be life-threatening. Mortality rates are about 60% and 15% in rupture of pseudocysts with and without hemorrhage, respectively, which is why this condition should be considered in all patients with complications of pancreatitis . Other complications include obstruction of the gastric outlet and biliary obstruction, as well as thrombosis of the portal venous system . Bleeding can also occur as a result of pseudoaneurysm formation, which is seen in about 10% of patients, most commonly involving the splenic artery and can necessitate rapid surgical treatment to prevent severe blood loss. Alcohol abuse as a cause of pseudocyst formation is known to significantly increase the risk for complications. in addition, the size and location of the cyst also contribute significantly to the complication rate as cysts that developed in the tail, or those smaller than 5 cm in diameter almost always regressed spontaneously .
Pseudocysts of the pancreas are formed due to leakage of pancreatic juices and their encapsulation into fibrous tissue as a result of increased pressures and damage of the pancreatic duct. The most common cause for this event is pancreatitis, either acute or chronic , while trauma, infection and neoplasia may be a potential cause as well. Sometimes, the cause of pseudocyst formation may remain unknown (idiopathic pancreatitis), which is seen in approximately 15-25% of cases .
It is estimated that around 15% of patients with acute pancreatitis develop pseudocysts, while significantly higher rates of about 40% are observed in chronic pancreatitis. . However, highest incidence rates were observed in chronic pancreatitis related to alcohol abuse , implying that alcohol abuse is one of the most important risk factors. Gallstone formation is also an important risk factor, because of its involvement in the pathogenesis of acute pancreatitis. Pseudocysts are usually seen in male adults, due to the fact that pancreatitis and alcohol abuse are more frequently encountered amongst males. Pancreatic pseudocyst formation can be seen in children as well, but the cause is primarily abdominal trauma.
The pathogenesis of pancreatic pseudocysts significantly differs in patients with acute and chronic pancreatitis . Regardless of the cause, the end-result is leakage of pancreatic juices consisting of amylase, lipase, and trypsin from the pancreatic duct and their entrapment in layers of fibrous tissue. The reason why the term "pseudocyst" is used is because there is an absence of the epithelial layer of cells, as the wall of the cyst is composed of fibroblasts and granulation tissue entirely. In the setting of acute pancreatitis, gallstones are the primary cause of impaired flow of bile and pancreatic content. Because of minimal damage to the pancreatic duct, smaller quantities of pancreatic juices exit the ducts and eventually form cysts that are less likely to cause complications. In the case of chronic pancreatitis with alcohol abuse, there is progressive damage to the parenchyma, including the pancreatic duct. Disruption of architecture by alcohol, activation of pancreatic stellate cells and subsequent collagen deposition lead to significant damage to the pancreatic duct, which may be massively dilated, or in severe cases obliterated, leading to accumulation of larger cysts . Sometimes, more than one cyst may be present, which is especially the case in chronic forms of pancreatitis .
Since the formation of pseudocysts is closely related to both acute and chronic pancreatitis and the risk factors for these conditions are preventable, the development of pseudocysts can be prevented. Alcohol consumption is established to be the single most important factor for the development of chronic pancreatitis, implying that reduction in alcohol consumption may significantly reduce the risk. On the other hand, acute pancreatitis is known to be associated with development of gallstones, which can be reduced through proper dietary habits and pharmacologic management when indicated.
Pancreatic pseudocyst is a formation composed of pancreatic secretions and juices enclosed by fibrous tissue. The term "pseudo" implies the cyst is lacking the epithelial cell layer and is formed under circumstances of extensive pressures in the pancreatic ducts, which most frequently develops in the setting of acute and chronic pancreatitis . It is established that approximately 15% of patients who suffer from acute pancreatitis develop pseudocysts, while much higher prevalence rates of almost 40% are observed in patients with chronic pancreatitis . Another potential cause, although much less common than the former two, can be trauma. The pathogenesis of pseudocyst formation in acute pancreatitis is significantly different as compared to in patients with chronic pancreatitis, but invariably involves structural changes and damage of the main pancreatic duct, leading to leakage of pancreatic juices. In acute pancreatitis, gallstones are the most common cause of ductal damage, usually in only a few sites, while chronic pancreatitis is characterized by chronic alcohol ingestion and severe disruption of the pancreatic parenchyma, lead to significant damage of the ductal system. In addition, extensive deposition of collagen and fibrosis occurs in the setting of chronic pancreatitis, which further contributes to development of pseudocysts. Pseudocysts usually develop over the course of several weeks after the onset of pancreatitis , and more than one cyst may develop, which is more commonly seen in patients with chronic pancreatitis. Pseudocysts may be asymptomatic and resolve without treatment, or they may cause significant morbidity and cause major complications. Abscess formation, rupture and hemorrhage can occur and it is established that mortality rates from rupture of pseudocysts without hemorrhage are around 14%, while accompanying hemorrhage raises mortality rates up to 60% . For these reasons, establishing a diagnosis early on may significantly reduce potentially fatal sequelae of this condition. The clinical presentation of patients may be asymptomatic, but when symptoms are present, they may be nonspecific and include abdominal pain, nausea, vomiting, bloating, fever and jaundice. Larger cysts may compress adjacent organs and cause symptoms such as cholangitis in the setting of biliary obstruction, while severe blood vessel obstruction, most commonly the splenic and superior mesenteric artery, can cause significant anemia and blood loss. In some cases, secondary infection may occur and lead to sepsis without appropriate treatment. Special attention should be given to lesions that are growing in size, because they are more prone to cause complications. Pancreatic pseudocysts can be initially detected by ultrasonography, while a definite diagnosis can be made by either computed tomography (CT) or magnetic resonance imaging (MRI). Because pancreatic pseudocysts comprise about 15% of all cystic formations in the pancreas, they should be differentiated from other cystic formations that may be malignant, which can sometimes require histological examination. Serial radiographic imaging should be performed to assess the progression of the lesion. Blood workup should be performed in all patients, including a complete blood count (CBC), levels of pancreatic enzymes, inflammatory markers, as well as evaluation of other organs, including the liver and the kidneys. In mild cases, spontaneous resolution frequently occurs and only conservative therapy may be sufficient, while more severe cases require a surgical approach. Regardless of the choice of surgery, the aim is either to provide a connection between the gastrointestinal system and the cyst so that internal drainage can be achieved, or to remove the cyst by excision. The choice of surgical treatment depends on the cyst size, location and on the presence of accompanying complications.
Pancreatic pseudocyst is a term that describes a formation of a cyst filled with pancreatic juice inside the pancreas, with the term "pseudo" (meaning "false") indicating that not all features are shared with classical cysts. In the vast majority of patients, pancreatic pseudocysts develop on the basis of either acute, but more commonly chronic pancreatitis, while trauma may also be a potential cause. Gallstones are the main risk factor and cause of acute pancreatitis, while alcohol abuse is the single most important risk factor for chronic pancreatitis. In either case, damage to the main duct of the pancreas causes leakage of pancreatic secretions and their subsequent entrapment into a layer of fibrous tissue. It is established that up to 15% of patients with acute and 40% of patients with chronic pancreatitis develop pseudocysts. Development of pseudocysts can have an asymptomatic course, meaning that symptoms are absent and the diagnosis can be made incidentally. But complications do occur in a substantial number of patients and some of them may be life-threatening, which is why a prompt diagnosis can be life-saving. Symptoms, when present, may include fever, abdominal pain, nausea, vomiting, appetite problems, and jaundice. Patients with a more severe course of the disease may experience anemia, hypotension, and shock. Complications include rupture of pseudocysts which can be accompanied with bleeding, while a secondary infection with development of sepsis may occur as well. For these reasons, ultrasonography is the initial diagnostic method of choice, as it is cheap and readily available, but more importantly, a very useful method to determine the cause of the symptoms. To confirm the exact location, size, but also number of cysts, either computed tomography (CT scan) or magnetic resonance imaging (MRI) should be performed. In some cases, when imaging techniques cannot differentiate pseudocysts with other similar lesions that can turn out to be cancerous, a sample of the cyst can be obtained for microscopic evaluation. Patients with mild complaints may not require therapy, as pseudocysts in the pancreas tend to resolve spontaneously within several weeks, but for patients with a severe disease course, treatment almost always includes some form of surgery. The goal of therapy is to eliminate the pseudocysts by either creating a pathway for them to drain into the gastrointestinal tract (because they are often in close proximity to the stomach or the duodenum) or in some cases, excision by either laparoscopic or open surgery can be performed. Pancreatic pseudocysts can pose a life-threatening risk to the patient, which is why a prompt diagnosis is essential in ensuring little or no complications of the disease.