Pseudocyst

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Pseudocyst
Pulmonary contusion pseudocyst CT.jpg
A chest CT scan revealing pulmonary contusions, pneumothorax, and pseudocysts
Specialty Respirology

Pseudocysts are like cysts, but lack epithelial or endothelial cells. Initial management consists of general supportive care. Symptoms and complications caused by pseudocysts require surgery. Computed tomography (CT) scans are used for initial imaging of cysts, and endoscopic ultrasounds are used in differentiating between cysts and pseudocysts. Endoscopic drainage is a popular and effective method of treating pseudocysts.

Contents

This is not to be confused with the so-called "pseudocystic appearance", mainly radiographically, of other lesions, such as Stafne static bone cyst and aneurysmal bone cyst [1] of the jaws.

Signs and symptoms

Pseudocysts are often asymptomatic. Symptoms are more common in larger pseudocysts, though the size and time present usually are poor indicators of potential complications. [2]

Pancreatic pseudocysts may cause abdominal pain, nausea and vomiting, a bloated feeling, and trouble eating or digesting food. They also may become infected, rupture, or block part of the intestine. Rarely, the infected pseudocyst causes jaundice or sepsis. [3]

Mediastinal pseudocysts, a rare form of pancreatic pseudocysts in the abdomen, may cause dysphagia, dyspnea, airway obstruction, or cardiac tamponade.[ citation needed ]

Adrenal pseudocysts may cause abdominal pain, along with various gastrointestinal symptoms such as nausea, vomiting, and constipation. [4]

Cause

Pancreatic pseudocysts are often caused by acute or chronic pancreatitis. [3] They may also be caused by trauma to the abdomen, with a higher frequency in children. [5] Pseudocysts are more often present in chronic pancreatitis patients than acute pancreatitis patients. Also, if the pancreatitis is alcohol induced, there is a higher incidence of pseudocysts. These alcohol-related pseudocysts account for 59%-78% of all pancreatic pseudocysts. Actual pancreatic pseudocyst incidence is small, at around 1.6%-4.5%, or .5-1 per 100,000 adults per year. [2]

Types of adrenal cysts include parasitic cysts, epithelial cysts, endothelial cysts, and pseudocysts. 56% of all adrenal cyst-like changes are pseudocysts, and only 7% of those pseudocysts are malignant or potentially malignant. [4]

The cause of adrenal pseudocysts is unknown. A few theories exist, but it is believed that repeated episodes of trauma, infection, or bleeding may cause collagen formation leading to the formation of a fibrous lining. [4]

Retinal pseudocysts may be related to geographic atrophy. A study found that 22% of eyes with geographic atrophy contained pseudocysts. [6]

In American trypanosomiasis (Chagas’ disease), the parasite Trypanosoma cruzi forms pseudocysts, particularly within muscular and neurological tissue. [7] Within these pseudocysts the parasites enter their amastigote stage, reproducing asexually, before rupturing from the pseudocyst and entering the bloodstream.

Diagnosis

Description

A pseudocyst is a cystic lesion that may appear as a cyst on scans, but lacks epithelial or endothelial cells. [4] An acute pancreatic pseudocyst is made of pancreatic fluids with a wall of fibrous tissue or granulation.[ citation needed ] Pseudocysts may form in a number of places, including the pancreas, abdomen, adrenal gland, and eye.

Pancreatic pseudocysts

The most common and effective method of diagnosing a pancreatic pseudocyst is with a CT scan. A pseudocyst generally appears as a fluid-filled mass. In some instances, other methods must be used to distinguish between a normal cyst and a pseudocyst. [3] This is usually accomplished with endoscopic ultrasound or with fine needle aspiration. [2]

Transabdominal ultrasound can be used to identify pseudocysts, which appear on the scan as echoic structures associated with distal acoustic enhancement. They tend to be round and enclosed in a smooth wall. Pseudocysts may appear more complex when young, hemorrhaged, or when complicated due to infection. The transabdominal ultrasound has a sensitivity rate in detection of pancreatic pseusocysts of 75%-90%, making it inferior to a CT scan, which has a rate of 90%-100%. [2]

CT scans are more accurate, and provide more detail regarding the pseudocyst and its surroundings. The CT scan's weakness is its lack of differentiation between pseudocysts and cystic neoplasm. Also, the intravenous contrast given at the time of the CT scan may worsen kidney dysfunction. [2]

MRI and MRCP are effective methods of detecting pseudocysts, but are not regularly used because CT scans offer most of the needed information. These scans do, however, provide better contrast, which allows for better characterization of fluid collections, depicting debris within the collections, and detection of bleeding. [2]

Endoscopic ultrasound is generally used as a secondary test to further evaluate the cysts found in other tests, and is used when determining if a cyst is a pseudocyst or not. [2]

Adrenal pseudocysts

Adrenal pseudocysts are found in much the same way as pancreatic pseudocysts, with CT scans. In addition, adrenalectomies are used to diagnose the lesion and sometimes relieve pain. [4]

Prevention

Because pseudocysts are closely related to other conditions, such as pancreatitis and alcohol use, the prevention of pseudocysts lies in the prevention of the main problem. [5]

Treatment

Not all cysts require treatment. Many pancreatic pseudocysts improve and disappear by themselves. If the cysts are small and are not causing symptoms, careful observation with periodic CT scans is often done. Pseudocysts that persist over many months or that cause symptoms require treatment. [3]

Supportive medical care used to help small pseudocysts go away includes the use of intravenous fluids, analgesics, and antiemetics. Doctors often recommend a low-fat diet for those who can tolerate oral intake. [2]

Surgery is usually required in the treatment of pseudocysts with symptoms or complications.[ citation needed ] There are three main methods for draining a pancreatic pseudocyst: endoscopic drainage, percutaneous catheter drainage, or open surgery. Endoscopic drainage tends to be the preferred method due to it being less invasive and having a high long-term success rate. [2]

Percutaneous drainage involves the guidance of a CT scan or ultrasound. A drainage catheter is placed into the fluid cavity to drain the fluid, which is then collected over several weeks into an external collection system. The catheter is removed when the drainage becomes minimal. Once the catheter is removed, contrast is injected into the cyst cavity to determine the remaining size and to monitor progress. The success rate is around 50%, and the unsuccessful drainages are mostly caused by large ductal leaks or blockage of the main pancreatic duct. This method is not recommended when patients cannot manage a catheter at home or with patients whose cysts contain bloody or solid material. [2]

Surgical drainage of a pseudocyst involves creating a pathway between the pseudocyst cavity and the stomach or small bowel. This method is generally only used if the patient cannot tolerate or failed percutaneous or endoscopic drainage. This method is more risky than the others. [2]

Endoscopic drainage is becoming the preferred method of draining pseudocysts because it is less invasive, does not require external drain, and has a large long-term success rate. Drainage is usually achieved with a transpapillary approach with ERCP. Sometimes a direct drainage across the stomach or duodenal wall is used instead. The transpapillary approach is used when the pseudocyst is in communication with the main pancreatic duct, and is also successful in patients with pancreatic duct disruption. Transgastric or transduodenal approaches are used when the pseudocyst is next to the gastro-duodenal wall. Endoscopic ultrasound is the most commonly used test to gather the needed information about the pseudocyst for this method. [2]

The endoscopic method depends on the presence of a bulge into the stomach or duodenum to determine the site for catheterization. Inherent risks include missing the pseudocyst, injuring nearby vessels, and inefficient placement of the catheter. In patients with chronic pseudocysts, this approach has a 90% success rate. Recurrence after drainage is around 4%, and the complication rate is below 16%. [2]

To treat adrenal pseudocysts, an adrenalectomy or laproscopy may be used. [4]

Related Research Articles

<span class="mw-page-title-main">Pancreatitis</span> Inflammation of the pancreas

Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancreatitis.

<span class="mw-page-title-main">Cyst</span> Closed sac growth on the body

A cyst, also traditionally known from Old English as a wen, is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac ; however, the distinguishing aspect of a cyst is that the cells forming the "shell" of such a sac are distinctly abnormal when compared with all surrounding cells for that given location. A cyst may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst may resolve on its own. When a cyst fails to resolve, it may need to be removed surgically, but that would depend upon its type and location.

<span class="mw-page-title-main">Bile duct</span> Type of organ

A bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates.

<span class="mw-page-title-main">Cholecystitis</span> Inflammation of the gallbladder

Cholecystitis is inflammation of the gallbladder. Symptoms include right upper abdominal pain, pain in the right shoulder, nausea, vomiting, and occasionally fever. Often gallbladder attacks precede acute cholecystitis. The pain lasts longer in cholecystitis than in a typical gallbladder attack. Without appropriate treatment, recurrent episodes of cholecystitis are common. Complications of acute cholecystitis include gallstone pancreatitis, common bile duct stones, or inflammation of the common bile duct.

<span class="mw-page-title-main">Cholecystectomy</span> Surgical removal of the gallbladder

Cholecystectomy is the surgical removal of the gallbladder. Cholecystectomy is a common treatment of symptomatic gallstones and other gallbladder conditions. In 2011, cholecystectomy was the eighth most common operating room procedure performed in hospitals in the United States. Cholecystectomy can be performed either laparoscopically, or via an open surgical technique.

<span class="mw-page-title-main">Endoscopic retrograde cholangiopancreatography</span> Use of endoscopy and fluoroscopy to treat and diagnose digestive issues.

Endoscopic retrograde cholangiopancreatography (ERCP) is a technique that combines the use of endoscopy and fluoroscopy to diagnose and treat certain problems of the biliary or pancreatic ductal systems. It is primarily performed by highly skilled and specialty trained gastroenterologists. Through the endoscope, the physician can see the inside of the stomach and duodenum, and inject a contrast medium into the ducts in the biliary tree and pancreas so they can be seen on radiographs.

<span class="mw-page-title-main">Acute pancreatitis</span> Medical condition

Acute pancreatitis (AP) is a sudden inflammation of the pancreas. Causes, in order of frequency, include: a gallstone impacted in the common bile duct beyond the point where the pancreatic duct joins it; heavy alcohol use; systemic disease; trauma; and, in minors, mumps. Acute pancreatitis may be a single event; it may be recurrent; or it may progress to chronic pancreatitis.

<span class="mw-page-title-main">Common bile duct stone</span> Medical condition

Common bile duct stone, also known as choledocholithiasis, is the presence of gallstones in the common bile duct (CBD). This condition can cause jaundice and liver cell damage. Treatments include choledocholithotomy and endoscopic retrograde cholangiopancreatography (ERCP).

<span class="mw-page-title-main">Pancreatic pseudocyst</span> Medical condition

A pancreatic pseudocyst is a circumscribed collection of fluid rich in pancreatic enzymes, blood, and non-necrotic tissue, typically located in the lesser sac of the abdomen. Pancreatic pseudocysts are usually complications of pancreatitis, although in children they frequently occur following abdominal trauma. Pancreatic pseudocysts account for approximately 75% of all pancreatic masses.

<span class="mw-page-title-main">Endoscopic ultrasound</span> Medical imaging procedure

Endoscopic ultrasound (EUS) or echo-endoscopy is a medical procedure in which endoscopy is combined with ultrasound to obtain images of the internal organs in the chest, abdomen and colon. It can be used to visualize the walls of these organs, or to look at adjacent structures. Combined with Doppler imaging, nearby blood vessels can also be evaluated.

Pancreatic diseases are diseases that affect the pancreas, an organ in most vertebrates and in humans and other mammals located in the abdomen. The pancreas plays a role in the digestive and endocrine system, producing enzymes which aid the digestion process and the hormone insulin, which regulates blood sugar levels. The most common pancreatic disease is pancreatitis, an inflammation of the pancreas which could come in acute or chronic form. Other pancreatic diseases include diabetes mellitus, exocrine pancreatic insufficiency, cystic fibrosis, pseudocysts, cysts, congenital malformations, tumors including pancreatic cancer, and hemosuccus pancreaticus.

<span class="mw-page-title-main">Ascending cholangitis</span> Medical condition

Ascending cholangitis, also known as acute cholangitis or simply cholangitis, is inflammation of the bile duct, usually caused by bacteria ascending from its junction with the duodenum. It tends to occur if the bile duct is already partially obstructed by gallstones.

<span class="mw-page-title-main">Hemosuccus pancreaticus</span> Medical condition

Hemosuccus pancreaticus is a rare cause of hemorrhage in the gastrointestinal tract. It is caused by a bleeding source in the pancreas, pancreatic duct, or structures adjacent to the pancreas, such as the splenic artery, that bleed into the pancreatic duct, which is connected with the bowel at the duodenum, the first part of the small intestine. Patients with hemosuccus may develop symptoms of gastrointestinal hemorrhage, such as blood in the stools, maroon stools, or melena, which is a dark, tarry stool caused by digestion of red blood cells. They may also develop abdominal pain. It is associated with pancreatitis, pancreatic cancer and aneurysms of the splenic artery. Hemosuccus may be identified with endoscopy (esophagogastroduodenoscopy), where fresh blood may be seen from the pancreatic duct. Alternatively, angiography may be used to inject the celiac axis to determine the blood vessel that is bleeding. This may also be used to treat hemosuccus, as embolization of the end vessel may terminate the hemorrhage. However, a distal pancreatectomy—surgery to remove of the tail of the pancreas—may be required to stop the hemorrhage.

<span class="mw-page-title-main">Percutaneous transhepatic cholangiography</span> Medical imaging of the biliary tract

Percutaneous transhepatic cholangiography, percutaneous hepatic cholangiogram (PTHC) is a radiological technique used to visualize the anatomy of the biliary tract. A contrast medium is injected into a bile duct in the liver, after which X-rays are taken. It allows access to the biliary tree in cases where endoscopic retrograde cholangiopancreatography has been unsuccessful. Initially reported in 1937, the procedure became popular in 1952.

Pancreatic abscess is a late complication of acute necrotizing pancreatitis, occurring more than 4 weeks after the initial attack. A pancreatic abscess is a collection of pus resulting from tissue necrosis, liquefaction, and infection. It is estimated that approximately 3% of the patients with acute pancreatitis will develop an abscess.

A pancreatic injury is some form of trauma sustained by the pancreas. The injury can be sustained through either blunt forces, such as a motor vehicle accident, or penetrative forces, such as that of a gunshot wound. The pancreas is one of the least commonly injured organs in abdominal trauma.

Cystogastrostomy is a surgery to create an opening between a pancreatic pseudocyst and the stomach when the cyst is in a suitable position to be drained into the stomach. This conserves pancreatic juices that would otherwise be lost. This surgery is performed by a pancreatic surgeon to avoid a life-threatening rupture of the pancreatic pseudocyst.

<span class="mw-page-title-main">Biloma</span> Circumscribed abdominal collection of bile outside the biliary tree

A biloma is a circumscribed abdominal collection of bile outside the biliary tree. It occurs when there is excess bile in the abdominal cavity. It can occur during or after a bile leak. There is an increased chance of a person developing biloma after having a gallbladder removal surgery, known as laparoscopic cholecystectomy. This procedure can be complicated by biloma with incidence of 0.3–2%. Other causes are liver biopsy, abdominal trauma, and, rarely, spontaneous perforation. The formation of biloma does not occur frequently. Biliary fistulas are also caused by injury to the bile duct and can result in the formation of bile leaks. Biliary fistulas are abnormal communications between organs and the biliary tract. Once diagnosed, they usually require drainage. The term "biloma" was first coined in 1979 by Gould and Patel. They discovered it in a case with extrahepatic bile leakage. The cause of this was trauma to the upper right quadrant of the abdomen. Originally, biloma was described as an "encapsulated collection" of extrahepatic bile. Biloma is now described as extrabiliary collections of bile that can be either intrahepatic or extrahepatic. The most common cause of biloma is trauma to the liver. There are other causes such as abdominal surgery, endoscopic surgery and percutaneous catheter drainage. Injury and abdominal trauma can cause damage to the biliary tree. The biliary tree is a system of vessels that direct secreations from the liver, gallbladder, and pancreas through a series of ducts into the duodenum. This can result in a bile leak which is a common cause of the formation of biloma. It is possible for biloma to be associated with mortality, though it is not common. Bile leaks occur in about one percent of causes.

<span class="mw-page-title-main">Choledochoduodenostomy</span>

Choledochoduodenostomy (CDD) is a surgical procedure to create an anastomosis, a surgical connection, between the common bile duct (CBD) and an alternative portion of the duodenum. In healthy individuals, the CBD meets the pancreatic duct at the ampulla of Vater, which drains via the major duodenal papilla to the second part of duodenum. In cases of benign conditions such as narrowing of the distal CBD or recurrent CBD stones, performing a CDD provides the diseased patient with CBD drainage and decompression. A side-to-side anastomosis is usually performed.

<span class="mw-page-title-main">Biliary endoscopic sphincterotomy</span> Use of endoscopy and fluoroscopy to treat and diagnose digestive issues.

Biliary endoscopic sphincterotomy is a procedure where the sphincter of Oddi and the segment of the common bile duct where it enters the duodenum are cannulated and then cut with a sphincterotome, a device that includes a wire which cuts with an electric current (electrocautery).

References

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