Pseudocysts are like cysts

Cyst

A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...

, but lack epithelial

Epithelium

Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...

 or endothelial

Endothelium

The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells. Endothelial cells line the entire circulatory system, from the heart...

 cells. Initial management consists of general supportive care. Symptoms and complications caused by pseudocysts require surgery. CT scans are used for initial imaging of cysts, and endoscopic ultrasounds

Endoscopic ultrasound

Endoscopic ultrasound or echo-endoscopy is a medical procedure in endoscopy is combined with ultrasound to obtain images of the internal organs in the chest and abdomen. It can be used to visualize the wall of these organs, or to look at adjacent structures...

 are used in differentiating between cysts and pseudocysts. Endoscopic drainage is a popular and effective method of treating pseudocysts.

Description

A pseudocyst is a cystic lesion that may appear as a cyst on scans, but lacks epithelial or endothelial cells. An acute pancreatic pseudocyst is made of pancreatic fluids

Pancreatic juice

Pancreatic juice is a liquid secreted by the pancreas, which contains a variety of enzymes, including trypsinogen, chymotrypsinogen, elastase, carboxypeptidase, pancreatic lipase, and amylase....

 with a wall of fibrous tissue or granulation

Granulation tissue

Granulation tissue is the perfused, fibrous connective tissue that replaces a fibrin clot in healing wounds. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size it heals...

. Pseudocysts may form in a number of places, including the pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

, abdomen

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

, adrenal gland

Adrenal gland

In mammals, the adrenal glands are endocrine glands that sit atop the kidneys; in humans, the right suprarenal gland is triangular shaped, while the left suprarenal gland is semilunar shaped...

, and eye

Human eye

The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

.

Etiology

Pancreatic pseudocysts are often caused by acute or chronic pancreatitis

Pancreatitis

Pancreatitis is inflammation of the pancreas. It occurs when pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years...

. They may also be caused by trauma

Trauma (medicine)

Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...

 to the abdomen, with a higher frequency in children. Pseudocysts are more often present in chronics 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..

Types of adrenal cysts include parasitic cysts, epithelial cysts, endothelial cysts, and pseudocysts. 56% of all adrenal cysts are pseudocysts, and only 7% of those pseudocysts are malignant or potentially malignant

Malignant

Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...

.

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.

Retinal pseudocysts may be related to geographic atrophy

Macular degeneration

Age-related macular degeneration is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults...

. A study found that 22% of eyes with geographic atrophy contained pseudocysts.

Symptoms

Pseudocysts are often asymptomatic

Asymptomatic

In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical...

. Symptoms are more common in larger pseudocysts, though the size and time present usually are poor indicators of potential complications.

Pancreatic pseudocysts may cause abdominal pain

Abdominal pain

Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem...

, nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

 and vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

, a bloated feeling, and trouble eating or digesting food. They also may become infected, be rupture, or block part of the intestine

Intestine

In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...

. Rarely, the infected pseudocyst causes jaundice

Jaundice

Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...

 or sepsis

Sepsis

Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...

.

Mediastinal pseudocysts, a rare form of pancreatic pseudocysts in the abdomen, may cause dysphagia

Dysphagia

Dysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, the term is sometimes used as a condition in its own right. Sufferers are sometimes unaware of their dysphagia....

, dyspnea

Dyspnea

Dyspnea , shortness of breath , or air hunger, is the subjective symptom of breathlessness.It is a normal symptom of heavy exertion but becomes pathological if it occurs in unexpected situations...

, airway obstruction, or cardiac tamponade

Cardiac tamponade

Cardiac tamponade, also known as pericardial tamponade, is an emergency condition in which fluid accumulates in the pericardium ....

.

Adrenal pseudocysts may cause abdominal pain, along with various gastrointestinal symptoms such as nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

, and constipation

Constipation

Constipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...

.

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. This is usually accomplished with endoscopic ultrasound

Endoscopic ultrasound

Endoscopic ultrasound or echo-endoscopy is a medical procedure in endoscopy is combined with ultrasound to obtain images of the internal organs in the chest and abdomen. It can be used to visualize the wall of these organs, or to look at adjacent structures...

 or with fine needle aspiration.

Transabdominal ultrasound

Abdominal ultrasonography

Abdominal ultrasonography is a form of medical ultrasonography to visualise abdominal anatomical structures...

 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%.

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

Pancreatic mucinous cystic neoplasm

Pancreatic mucinous cystic neoplasm, also mucinous cystic neoplasm of the pancreas and mucinous cystic tumour, is a grouping of cystic neoplasms that arise from the pancreas...

. Also, the intravenous contrast

Contrast medium

A medical contrast medium is a substance used to enhance the contrast of structures or fluids within the body in medical imaging...

 given at the time of the CT scan may worsen kidney dysfunction.

MRI and MRCP

Magnetic resonance cholangiopancreatography

Magnetic resonance cholangiopancreatography is a medical imaging technique that uses magnetic resonance imaging to visualise the biliary and pancreatic ducts in a non-invasive manner...

 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.

Endoscopic ultrasound

Endoscopic ultrasound

Endoscopic ultrasound or echo-endoscopy is a medical procedure in endoscopy is combined with ultrasound to obtain images of the internal organs in the chest and abdomen. It can be used to visualize the wall of these organs, or to look at adjacent structures...

 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.

Adrenal Pseudocysts

Adrenal pseudocysts are found in much the same way as pancreatic pseudocysts, with CT scans. In addition, adrenalectomies

Adrenalectomy

Adrenalectomy is the surgical removal of one or both adrenal glands. It is usually advised for patients with tumors of the adrenal glands. The procedure can be performed using an open incision or laparoscopic technique....

 are used to diagnose the lesion and sometimes relieve pain.

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.

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

Low-fat diet

According to the USDA, a low-fat diet as the name implies is a diet that consists of little fat, especially saturated fat and cholesterol, which are thought to lead to increased blood cholesterol levels and heart attack...

 for those who can tolerate oral intake.

Surgery

Surgery

Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...

 is usually required in the treatment of pseudocysts with symptoms or complications

Complication (medicine)

Complication, in medicine, is an unfavorable evolution of a disease, a health condition or a medical treatment. The disease can become worse in its severity or show a higher number of signs, symptoms or new pathological changes, become widespread throughout the body or affect other organ systems. A...

. There are three main methods for draining a pancreatic pseudocyst: endoscopic drainage, percutaneous

Percutaneous

In surgery, percutaneous pertains to any medical procedure where access to inner organs or other tissue is done via needle-puncture of the skin, rather than by using an "open" approach where inner organs or tissue are exposed .The percutaneous approach is commonly used in vascular procedures...

 catheter

Catheter

In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...

 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.

Percutaneous drainage involves the guidance of a CT scan or ultrasound

Ultrasound

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

. A drainage catheter

Catheter

In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...

 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

Pancreatic duct

The pancreatic duct, or duct of Wirsung , is a duct joining the pancreas to the common bile duct to supply pancreatic juices which aid in digestion provided by the "exocrine pancreas"...

. This method is not recommended when patients cannot manage a catheter at home or with patients whose cysts contain bloody or solid material.

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.

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

Stomach

The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...

 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.

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%.

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

Prevention

Because pseudocysts are closely related to other conditions, such as pancreatitis

Pancreatitis

Pancreatitis is inflammation of the pancreas. It occurs when pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years...

 and alcohol use, the prevention of pseudocysts lies in the prevention of the main problem.

Case Studies

In an unusual case in 2008, a child in Taiwan developed an intra-abdominal abscess caused by salmonella

Salmonella

Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...

. The child suffered from fever

Fever

Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

, abdominal pain, and distention for a week, along with vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

 and mild diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

. His abdomen was firm, distended, and tender, but lacked a palpitated mass. Abdominal x-rays

Abdominal x-ray

An abdominal x-ray is an x-ray of the abdomen. It is sometimes abbreviated to AXR, or KUB .-Diagnostic Tool:...

 “showed increased gas in the small bowel and soft-tissue density occupying the left abdomen.” A CT scan of the abdomen showed a huge mass containing various-sized cystic lesions with thick walls. Upon examination of the fluid in the mass, Salmonella enterica

Salmonella enterica

Salmonella enterica is a rod-shaped flagellated, facultative anaerobic, Gram-negative bacterium, and a member of the genus Salmonella.- Epidemiology :...

was found. The conclusion of the tests was that it was an inflammatory pseudocyst with abscess

Abscess

An abscess is a collection of pus that has accumulated in a cavity formed by the tissue in which the pus resides due to an infectious process or other foreign materials...

 formation. “Infectious complications of intra-abdominal cystic lymphangiomas have been reported due to Gram-positive bacteria, …Gram-negative bacteria [including salmonella], …and Mycobacterium tuberculosis

Mycobacterium tuberculosis

Mycobacterium tuberculosis is a pathogenic bacterial species in the genus Mycobacterium and the causative agent of most cases of tuberculosis . First discovered in 1882 by Robert Koch, M...

.” Only three other cases of salmonella infection of this kind, and only one of those was the same strain as the child’s in this case.