Clinical History
27-year-old female patient with abdominal pain.
The diagnosis of pancreatic pseudocyst was established by aspiration of the lesion which showed high level of amylase. Transgastric endoscopic drainage with a catheter and follow-up stenting was done. A follow-up abdominal CT showed resolution of the pseudocyst.
Imaging Findings
Initial transgastric endoscopic ultrasound was performed which demonstrated a large containing low internal echo cystic lesion. There was no indication for internal septation or intramural nodularity.
Abdominal CT was performed at the time of admission which showed a 9 x 7.6 cm pseudocyst within the left upper quadrant of the abdomen with air-fluid level and a drainage catheter with its proximal aspect extending from the stomach lumen. Associated stranding of the mesentery was seen, along with a small amount of free fluid in the pelvis and retroperitoneal spaces.
Follow-up endoscopic images demonstrate process of replacement of the obstructed catheter by a 10 mm stent.
Finally, a follow-up abdominal CT obtained 4 months after the last procedure revealed the pigtail catheter extending from the lumen of the stomach into the peripancreatic fat. Complete resolution of the pseudocyst was seen.
Discussion
Pancreatic pseudo-cysts are collections of pancreatic juice surrounded by a thick, fibrous capsule, and are often seen as a complication of pancreatitis. Reported prevalence rates range from 6% to 18.5% [1, 2] in acute pancreatitis, and 20-40% in chronic pancreatitis [3].
Computed Tomography (CT) is often the imaging method of choice, with 90% to 100% sensitivity and 98% specificity. A thick-walled fluid filled mass adjacent to the pancreas in a patient with a history of acute or chronic pancreatitis is virtually pathognomonic for a pancreatic pseudocyst, and this finding does not require confirmation with another diagnostic modality.
Abdominal ultrasound can also be used when clinical suspicion is low, but has a lower sensitivity ranging from 75% to 90% [4]. And the most accurate test is an endosonography, with a sensitivity of 93% to 100% and specificity of 92% to 98% [5].
While most pseudocysts resolve with supportive medical care, those that are large, symptomatic, or persist over 6 weeks often require drainage. If drainage is required, several methods can be employed including endoscopy, interventional radiology, laparoscopy or surgery. The endoscopic approach is often favoured because it is less invasive than the other options, and it has a high long-term success rate.
However, percutaneous, surgical, and endoscopic pseudocyst drainage procedures have not been directly compared in high-quality prospective randomized studies and the preferred approach still varies based on patient preferences and local expertise [4].
Differential Diagnosis List
Pancreatic pseudocyst treated with a transgastric drainage catheter and stent placement.
Pancreatic cystic neoplasm
Pancreatic pseudocyst
Peripancreatic abscess
Final Diagnosis
Pancreatic pseudocyst treated with a transgastric drainage catheter and stent placement.
