Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Pancreatic pseudocyst of the mediastinum
- Radiologic Findings
- Fig 1. Chest PA shows large left pleural effusion with basal lung atelectasis.
Fig 2-8. On CT image, multiloculated left pleural effusion with pleural enhancement is noted. Multiloculated fluid collection with peripheral enhancement is also noted in the posterior mediastinum, around the esophagus and at the posterior aspect of pericardium. The lesion extends inferiorly along the posterior wall of the esophagus, gastroesophageal junction, stomach and into the peripancreatic region.
Fig 9-12. On coronal reconstructed image, fluid collection communicated with dilated pancreatic duct in the region of the pancreas tail. These findings suggest disruption of the pancreatic duct, rupture of pseudocyst and extension of pancreatic fluid to the mediastinum and the pleura.
The levels of amylase and lipase were elevated of 397 and 342 U/L on the analysis of left pleural effusion.
- Brief Review
- Pancreatic pseudocysts are a common complication of both acute and chronic pancreatitis. They are usually located in peripancreatic area and very rarely they may reach the mediastinum.
Patho-physiologically, mediastinal pseudocyst can develop after rupture of the pancreatic duct into the retroperitoneal space. The pancreatic fluid then tracks through the diaphragmatic openings such as esophageal and aortic hiatus into the mediastinum.
Symptoms are primarily the results of compression or invasion of the mediastinal structures and may include dysphagia, odynophagia, weight loss, abdominal, chest and/or back pain, dyspnea, and cough.
A chest radiograph may be undiagnostic but can show retrocardiac opacity, pleural effusion, and atelectasis of basal lungs. Contrast-enhanced CT scan can show a thin-walled low-attenuating cystic mass extended from the pancreas into the mediastinum. Magnetic resonance cholangiopancreatography can help identify the connection between the mediastinal and abdominal pseudocyst in cases where it not so evident on CT scan. Endoscopic ultrasound is increasingly used in evaluating pancreatic cysts due to its advantages in delineating contents and wall of the cysts.
An elevated amylase or lipase level in the aspirated fluid from the mediastinal pseudocyst can confirm the diagnosis.
Spontaneous regression of mediastinal pseudocysts is rare and therapeutic intervention is frequently required. It includes surgical drainage such as open laparotomy and percutaneous approach, and endoscopic drainage methods.
Pseudocysts should be considered as a differential diagnosis in the evaluation of mediastinal masses in patents with a history of pancreatitis.
- References
- 1. Drescher R, Koster O, Lukas C. Mediastinal pancreatic pseudocyst with isolated thoracic symptoms: a case report. Journal of Medical Case Reports 2008, 2:180.
2. Gupta R, Munoz JC, Garg P, et al. Mediastinal Pancreatic Pseudocyst-A Case Report and Review of the Literature. Medscape General Medicine. 2007; 9(2): 8.
3. Kirchner SG, Heller RM, Smith CW. Pancreatic pseudocyst of the Mediastinum. Radiology 1997, 123:32-42.
- Please refer to
- Case 866
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- Keywords
- Mediastinum, Pleura,