OTHER MEETINGS
View other valuable, upcoming pediatric surgery-related meetings.
To submit a meeting, click here.
Pancreatic Cysts
Neoplastic Cysts
Papillary neoplastic cysts, which are rare in
childhood, should be assumed to cause cancer. Only by looking at the
cyst under the microscope after surgery can doctors tell if the cyst is
cancerous. They are easily ruptured, and the fluid inside the cyst is
extremely irritating to the inside of the belly.
Figure 1:
A pseudocyst of the pancreas is seen as the dark oval (arrows)
structure in the area of the “head” of the pancreas
Pancreatic Pseudocysts
Pancreatic pseudocysts are abnormal swellings that
look like cysts (Figure 1).
They usually happen after new inflammation of the
pancreas or injury. Pancreatic pseudocysts make up more than 75% of
cystic problems of the pancreas; they are located most often behind the
stomach. The wall of the cyst is made of inflammatory tissue which can
be flimsy or tough, and the lining lacks the normal cells present in
true cysts.
A pseudocyst may or may not connect with the
pancreatic drainage system, but when it does, pancreatic enzyme
(amylase) levels frequently exceed 3000 U/L.
These cysts are usually one big cyst, and they can hold
more than 1 liter of fluid. 70% of these cysts may result from injuries.
Pseudocysts occasionally occur after pancreatitis caused by unknown
factors, and rarely a stone stuck in the main bile tube, a duplication
cyst, or mumps may cause a pseudocyst to form.
Patients with pancreatic pseudocysts often were injured
by a blow to the belly or had an illness resembling pancreatitis weeks
to months earlier. Upper belly pain and loss of appetite progressing to
nausea, vomiting, and weight loss often follow. Eventually one is able
to feel a round mass in the upper part of the belly.
The growing pseudocyst may push the stomach up and
forward and the colon down and forward. A portion of the first part of
the small intestine may be narrowed or blocked. Increased fluid inside
the belly may develop with large increases in pancreatic enzyme levels.
Abdominal ultrasound and CT are generally diagnostic (Figure 1).
Small cysts not interfering with bowel function often can
be followed with repeated ultrasound or CT until they ultimately
disappear. For acute pseudocysts resulting from injuries, needle
drainage through the skin sometimes is effective. Complications from
untreated large pseudocysts may include bleeding, infection, rupture
with severe belly pain, and blockage of bowel, pancreatic, or bile tube
function.
Proper treatment depends mainly on the age of the cyst
and the strength and thickness of the cyst wall on CT. Of the patients
with moderately severe acute pancreatitis, including pancreatitis caused
by injuries, who get pseudocysts, 50% go away on their own within 3 to 4
weeks when treated without surgery, unless infection occurs.
When a pseudocyst has achieved chronic status, it is not
likely to go away on its own, and continued medical treatment without
surgery may lead to complications. Cysts only in the tail (left side) of
the pancreas may be removed by removing that end of the pancreas without
removing the spleen.
A large pseudocyst in the middle part (body) of the
pancreas, pushing against the stomach, is best treated by draining the
cyst into the stomach either by using telescopic equipment placed
through the patient’s mouth into their stomach or by surgery. The
opening through the back wall of the stomach into the cyst should be
made big enough so that it will not close before the cyst has collapsed
completely. Bleeding after surgery can occur.
For pseudocysts of the head of the pancreas or for cysts
in the body that are not right next to the stomach, drainage into the
intestine is better. X-ray dye studies after surgery may show the cyst
filled with dye for weeks or months until the cyst cavity is no longer
present. There are some reports of successful needle drainage through
the skin of chronic pseudocysts, especially for pancreatitis caused by
injuries when the pseudocyst does not have a known connection with the
pancreatic duct (tube) system.
A pancreatic pseudocyst that goes into the chest is a
rare problem that may show up as an upper belly mass with either (1)
fluid in the chest outside of the lung with a high enzyme (amylase)
level or (2) a chest mass. CT scan may show the whole pseudocyst above
and below the diaphragm.
The most successful surgery in these patients has been
drainage of the major pseudocyst into the intestine. Drainage inside the
chest of these pseudocysts commonly leads to the same problem again.
Occasionally a cyst that is only inside the chest that has been there
since birth may contain pancreas tissue. In these cases, the cyst should
be removed through the chest.
SUGGESTED READING
Nealon WH, Walser E: Main pancreatic ductal anatomy can
direct choice of modality for treating pancreatic pseudocysts (surgery
versus percutaneous drainage). Ann Surg 235: 751-758, 2002.
This article shows how pancreatic ductal anatomy in
patients with complicated pancreatitis should guide the selection of
treatment.
Article and graphics adapted from O'Neill: Principles of
Pediatric Surgery. © 2003, Elsevier.
|
