Chapter17: Peritoneal Cavity

Question 1

What is the function of peritoneal cavity?

Answer 1

The peritoneal cavity houses the abdominal viscera and is lined by a single layer of mesothelial
cells;thesecover the visceral and parietal surfaces and are supported by a thin layer of
connective tissue to form the peritoneum.

Question 2

OUTILINE

Here we discuss inflammatory, infectious, and
neoplastic disorders of the peritoneal cavity and retroperitoneal space.

Although they are less
common than inflammatory and infectious processes, tumors can carry a grave prognosis and,
thus, deserve discussion.

Answer 2

• inflammatory,
• infectious, and
• neoplastic disorders of the peritoneal cavity and
• retroperitoneal space.

Question 3

Peritonitis may result from bacterial invasion or chemical irritation and is most often due to:

Answer 3

• Leakage of bile or pancreatic enzymes, which produces sterile peritonitis
• Perforation or rupture of the biliary system that evokes a highly irritating peritonitis, usually complicated by bacterial superinfection
• Acute hemorrhagic pancreatitis (see Chapter 19 ), which is associated with leakage of pancreatic enzymes and fat necrosis. Globules of fat may be found in the peritoneal fluid. Damage to the bowel wall may allow bacteria to spread to the peritoneal cavity, leading to a frank suppurative exudate after 24 to 48 hours.
• Foreign material, including that introduced surgically (e.g., talc and sutures), that induces foreign body–type granulomas and fibrous scarring
• Endometriosis, which causes hemorrhage into the peritoneal cavity, where it acts as an irritant
• Ruptured dermoid cysts release keratins that invoke an intense granulomatous reaction
• Perforation of abdominal viscera, as described below

Question 4

When does Bacterial peritonitis occur?

Answer 4

Bacterial peritonitis occurs when bacteria from the gastrointestinal lumen are released into the
abdominal cavity, typically following perforation.

Question 5

Bacterial peritonitis occurs most commonly as a complication of what?

Answer 5

• acute appendicitis,
• peptic ulcer,
• cholecystitis,
• diverticulitis, and
• intestinal ischemia.

Acute salpingitis, abdominal trauma, and peritoneal dialysis are other potential sources of
contaminating bacteria.

Question 6

What bacterial are most commonly implicated in Bacterial peritonitis?

Answer 6

Although E. coli, streptococci, S. aureus, enterococci, and C. perfringens are implicated most often, _virtually any bacteria can be associated with bacterial
peritonitis._

Question 7

When does Spontaneous bacterial peritonitis develops?

Answer 7

in the absence of an obvious source of
contamination.

It is an uncommon disorder that is seen most often in patients with cirrhosis and ascites; 10% of such individuals develop spontaneous bacterial peritonitis.

Children, particularly
those with nephrotic syndrome, may also develop spontaneous bacterial peritonitis.

The
manner by which bacteria gain access to the peritoneal cavity is unknown, but the organisms
identified most often are E. coli and pneumococci, suggesting sources in the GI tract or the
lungs, respectively.

Question 8

What bacterial are mostl commonly identified in Spontaneous Bacterial Peritonitis?

Answer 8

The manner by which bacteria gain access to the peritoneal cavity is unknown, but the organisms
identified most often are E. coli and pneumococci, suggesting sources in the GI tract or the lungs, respectively.

Question 9

What is the morphology of Bacterial peritonitis?

Answer 9

Normally glistening serosal and peritoneal surfaces become dull and lusterless, and serous or slightly turbid fluid begins to accumulate within 2 to 4 hours of infection.

As the infection progresses, creamy suppurative material that may be extremely viscous accumulates.

The volume of fluid varies enormously; it may be localized by the omentum and viscera to a small area or may fill the abdominal cavity.

Exudate may collect
around the liver to form subhepatic and subdiaphragmatic abscesses

Question 10

What is the composition of cellular inflammatory response in Bacterial peritonitis?

Answer 10

The cellular inflammatory response is composed primarily of dense collections of neutrophils
and fibrinopurulent debris that coat the viscera and abdominal wall.

Question 11

In Bacterial peritonitis the reaction usually
remains superficial and does not penetrate deeply.

However there is one exception, what is this?

Answer 11

One exception is tuberculous peritonitis,
which typically studs the serosal and peritoneal surfaces with small, pale granulomas.

Question 12

While bacterial peritonitis can be fatal, the inflammatory process can also heal, either what?

Answer 12

spontaneously or as a result of therapy.

It may resolve completely; undergo organization into
fibrous adhesions; or become walled off in abscesses that may persist (potentially serving as
new sources of infection) or heal.

Question 13

What is Sclerosing retroperitonitis?

Answer 13

,also known as idiopathic retroperitoneal fibrosis or Ormond disease,

is characterized by dense fibrosis that may extend to involve the mesentery.

Although the cause of sclerosing retroperitonitis is unknown, it is thought to be an inflammatory process. Because the process frequently compresses the ureters, this entity is described in more detail in Chapter
21 .

Question 14

Describe the cyst in peritoneal cavity.

Answer 14

Cysts may develop within the abdominal cavity and are frequently attached to the peritoneum.

They can be quite large, sometimes presenting as palpable abdominal masses.

Question 15

Where do cysts in the peritoneal cavity originate?

Answer 15

The origins of such cysts are diverse; they can develop from:

• “blind” lymphatic channels;
• foregut or hindgut diverticulae that pinch off during development;
• the urogenital ridge or its derivatives (i.e., the urinary tract and male and female genital tracts);
• walled-off infections; or as a sequela of pancreatitis (pseudocysts).

Question 16

Most tumors of the peritoneum are malignant and can be divided into what?

Answer 16

• primary and
• secondary forms.

Question 17

Primary tumors arising from peritoneal lining

Answer 17

mesotheliomas that are similar to tumors of the
pleura and pericardium.

Question 18

Peritoneal mesotheliomas are almost always associated with what?

Answer 18

significant asbestos exposure.

It has been hypothesized that swallowed asbestos fibers somehow penetrate through the intestinal wall to reach the peritoneum.

As with pleural mesothelioma, the
histopathologic diagnosis can be difficult.

The **differential diagnosis includes metastatic
adenocarcinoma,** which can be distinguished from mesothelioma using a variety of
immunohistochemical markers ( Chapter 15 ).

Question 19

Rarely, primary benign and malignant soft-tissue tumors develop within the peritoneum and
retroperitoneum.

What is the most common of these?

Answer 19

The most common of these is desmoplastic small round cell tumor .

This aggressive tumor occurs in children and young adults.

The neoplasm is characterized by a
reciprocal chromosomal translocation, t(11;22)(p13;q12) that results in fusion of genes associated withEwing sarcoma (EWS)andWilms tumor (WT1).

Morphologically, the tumor
bears a resemblance to Ewing sarcoma and related tumors

Question 20

Secondary tumors of the peritoneum are, in contrast, quite common.

What are the secondary tumors of the peritoneum?

Answer 20

In any form of advanced cancer, direct spread to the serosal surface or metastatic seeding (peritoneal carcinomatosis) may occur.

Question 21

The most common tumors producing diffuse serosal implants are what?

Answer 21

• ovarian and
• pancreatic adenocarcinoma.

Question 22

Appendiceal mucinous carcinomas may produce what?

Answer 22

pseudomyxoma peritoneii.

Question 23

However, any intra-abdominal malignancy, as well as a wide variety of tumors of extra-abdominal origin, may spread to the peritoneum

T or F

Answer 23

True