Pseudocyst

Key takeaways

Pseudocyst belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pseudocyst to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pseudocyst from memory before moving on to harder problems.

Reference excerpt

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. 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 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. 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. Mediastinal pseudocysts, a rare form of pancreatic pseudocysts in the abdomen, may cause dysphagia, dyspnea, airway obstruction, or cardiac tamponade. Adrenal pseudocysts may cause abdominal pain, along with various gastrointestinal symptoms such as nausea, vomiting, and constipation.

Cause Pancreatic pseudocysts are often caused by acute or chronic pancreatitis. They may also be caused by trauma to the abdomen, with a higher frequency in children. 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. 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. 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. A study found that 22% of eyes with geographic atrophy contained pseudocysts. In American trypanosomiasis (Chagas’ disease), the parasite Trypanosoma cruzi forms pseudocysts, particularly within muscular and neurological tissue. 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. An acute pancreatic pseudocyst is made of pancreatic fluids with a wall of fibrous tissue or granulation. 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. This is usually accomplished with endoscopic ultrasound or with fine needle aspiration. 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%. 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. 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. 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.

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.

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.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Pseudocyst

Start with the simplest possible case. Write down what Pseudocyst claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pseudocyst before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pseudocyst ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pseudocyst

In research: Pseudocyst appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pseudocyst in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pseudocyst is common in secondary-school and first-year university syllabi. It links to neighbouring topics Gross pathology, so understanding it makes those chapters shorter.
In everyday life: Look for Pseudocyst outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Pseudocyst in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pseudocyst means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pseudocyst out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pseudocyst in simple terms?

Pseudocysts are like cysts, but lack epithelial or endothelial cells. Initial management consists of general supportive care.

Why does Pseudocyst matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pseudocyst?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pseudocyst.