What is the clinical significance of an incidentally discovered pericardial cyst on a computed tomography (CT) scan?

Clinical Significance of Incidentally Discovered Pericardial Cysts on CT Scan

Incidental pericardial cysts do not require follow-up unless they are large and risk compression of adjacent structures. 1

What Are Pericardial Cysts?

• Pericardial cysts are rare mediastinal masses with an incidence of 1 in 100,000 patients, representing 6% of mediastinal masses and 33% of mediastinal cysts 1
• They may be congenital or acquired (inflammatory cysts from rheumatic disorders, bacterial infection, trauma, or cardiac surgery) 1
• Typically unilocular or multilocular with diameters ranging from 1-5 cm 1
• Most commonly located at the right cardiophrenic angle 1

Imaging Characteristics

• On chest radiographs, they appear as oval, homogeneous radio-dense lesions 1
• CT scan can determine density readings and relationship to surrounding structures 1
• MRI may provide additional characterization when needed 1
• Echocardiography is useful but often requires additional imaging by CT or MRI for complete evaluation 1

Clinical Significance

• Most pericardial cysts (>75%) are asymptomatic and discovered incidentally on imaging 2
• When symptomatic, patients may present with:
  • Chest discomfort or pain 3, 4
  • Dyspnea 3, 4
  • Cough 5, 4
  • Palpitations due to cardiac compression 1, 6

Management Approach

• For asymptomatic, small pericardial cysts:

  • Conservative management with routine follow-up is recommended 3, 7
  • No specific follow-up is required unless they are large 1

• For symptomatic or large cysts:

  • Surgical resection or percutaneous aspiration should be considered 1, 3
  • Video-assisted thoracoscopic surgery (VATS) is commonly used for excision 3
  • Median sternotomy may be necessary for cysts in difficult locations 6, 5

Potential Complications

• Although rare, pericardial cysts can cause:
  • Compression of cardiac chambers 1
  • Compression of adjacent structures like bronchi 5
  • Cardiac arrhythmias (rare but documented) 6
  • Rupture (extremely rare) 1

Key Points for Clinical Practice

• The American College of Radiology Incidental Findings Committee recommends no follow-up for incidental pericardial cysts unless they are large and risk compression of adjacent structures 1, 2
• Size and location are important factors in determining potential clinical significance 1
• Spontaneous resolution of pericardial cysts has been reported, though rare 7
• Surgical intervention should be reserved for symptomatic patients or when diagnosis is uncertain and malignancy is suspected 5

Pitfalls to Avoid

• Don't confuse pericardial cysts with other mediastinal masses such as thymic cysts, bronchogenic cysts, or neoplasms 1
• Don't assume all pericardial masses are benign; atypical features warrant further investigation 2
• Don't automatically recommend surgical intervention for asymptomatic small cysts 3, 7
• Don't overlook symptoms that develop over time in patients with previously asymptomatic cysts 5