Pericardial cyst occurs rarely, with one person affected in 100,000 [1] [2]. The cysts constitute less than ten percent of mediastinal masses and about a third of mediastinal cysts [3]. They range in size from about 2 cm to almost 30 cm [4], with a layer of mesothelial cells lining them [2]. The cysts are usually congenital [1], and originate from the pericardial coelom as the result of abnormal embryonic development [5]. They are most often found at the right cardiophrenic angle [2]. Alternative names include springwater cyst because the fluid inside the cysts has been characterized as crystal clear [5]. Otto Pickhardt performed the first resection of a pericardial cyst and found an orange-sized, shiny cyst [5] [6].

Most patients are asymptomatic and the cysts are discovered on radiographs or echocardiograms obtained for unrelated reasons. Symptoms, if they occur, are most often caused by compression of neighboring structures. The most frequent symptoms of pericardial cysts are chest pain, dyspnea, and cough.

Rare but serious complications can arise. One of these is cardiac tamponade, which is usually caused by rupture of the cyst inside the pericardium [6], or by hemorrhage from the cyst [7] [8]. Chest pain and signs of respiratory tract infection have been reported [9]. Pulmonary stenosis, right ventricular outflow obstruction, and infection of the cyst can also occur [10]. Giant cysts have been described, one that slowly grew to a size that held two and a half liters of fluid [11], and another that resulted in the unusual symptom of recurrent syncope because of compression of the right ventricle [12]. A pericardial cyst may infrequently erode adjacent structures, such as the superior vena cava [13], or partially erode into the right ventricular wall [14]. The cysts can occasionally resolve without intervention.

Imaging methods include plain radiography, echocardiography, computed tomography (CT) scans, and magnetic resonance imaging (MRI). Computed tomography is regarded as the method of choice, because it is helpful in determining the location of lesions, and detects pericardial thickening, and other defects [2] [15]. CT can distinguish masses derived from mediastinal structures from those arising outside the mediastinum. CT scans can also differentiate cystic structures from solid ones. In problematic cases, injection of contrast material into the cyst may aid in the diagnosis [2]. Most pericardial cysts show well-defined, non-enhancing attenuation on CT scans [15]; however, protein content in the cysts interferes with attenuation. Hemorrhagic cysts show hyperattenuation.

MRI is also helpful in diagnosis and follow-up examinations. It yields a high signal intensity on T2 weighted images, and a low signal intensity on T1 weighted images. This is altered in cysts containing a high concentration of protein. Diffusion weighted images may be useful in certain cases [16].

Ultrasound techniques are not the generally favored method for diagnosing pericardial cysts, although echocardiography can be a useful tool for determining the location of the cyst, and for differentiating it from other structural anomalies [2]. Echocardiography has the advantage over CT in that no ionizing radiation is involved [1].

• Mediastinal Mass

  Patient with a mediastinal mass may be diagnosed incidentally or following evaluation for the symptoms due to compressive effects on the adjoining structures. Pericardial cysts account to 6% of mediastinal masses. [ncbi.nlm.nih.gov]

  Pericardial cysts represent 6% of mediastinal masses. See the differential diagnosis of caridophrenic angle masses here. About radiologypics I am a radiology physician from California, USA. [radiologypics.com]

  […] lesion mediastinal teratoma Morgagni hernia Promoted articles (advertising) [radiopaedia.org]

• Anterior Mediastinal Mass

  View Article PubMed Google Scholar Uchiyama A, Shimizu S, Murai H, Ohshima A, Konomi H, Ogura Y, Ishikawa N, Yamashita H, Matsumoto S, Kuroki S, Tanaka M: Infrasternal mediastinoscopic surgery for anterior mediastinal masses. [casesjournal.biomedcentral.com]

Although definitive diagnosis and management were not accomplished at the bedside in this case, an abnormal finding on FOCUS prompted further investigation and timely treatment. [ncbi.nlm.nih.gov]

Table 2 Summary of published case series of patients with pericardial cysts First author/reference Publication year Total no. of patients No. of symptomatic patients Presenting symptoms Treatment in symptomatic patients Feigin 1 1977 82 34 Chest pain, [academic.oup.com]

Surgical resection is the only definitive treatment for pericardial cysts. [ismics.org]

This cyst generally presents a favorable prognosis, although its natural history is not completely known. 3 The literature reports cases ranging from spontaneous disappearance to recurrence after surgical resection, as well as serious, even fatal complications [revespcardiol.org]

Signal characteristics are those of fluid and include 4 : T1: typically low signal (occasionally can be high signal if contains proteinaceous material) T2: high signal T1 C+ (Gd): no enhancement Treatment and prognosis They are benign lesions. [radiopaedia.org]

Furthermore, neither of the available non-invasive imaging modalities is sufficiently reliable to differentiate pericardial cysts from other pericardial masses with similar appearances but with different prognosis and treatments. 1 The differential diagnosis [elsevier.pt]

Prognosis The prognosis after resection of a mediastinal tumor varies widely, depending on the type of lesion resected. After resection of mediastinal cysts and benign tumors, the prognosis is generally excellent. [9] Donahue JM, Nichols FC. [emedicine.medscape.com]

What is the prognosis of Pericarditis? Will it ever go away? Please help! Allan_Klein,_MD: The connective tissue disease associated pericarditis is driven by the rheumatologic condition. Therefore, adequate treatment of the CTD is important. [my.clevelandclinic.org]

A pericardial cyst is a rare finding and is frequently congenital in etiology. Pericardial cysts are most commonly incidental findings and have no clinical significance. [healio.com]

The etiology of sudden cardiac death involves a wide range of diseases, but seldom pericardial cysts. A pericardial cyst is an uncommon cyst usually located in the middle mediastinum and rarely in the posterior part. [ncbi.nlm.nih.gov]

A concept of etiology and report of cases. J Thorac Surg 1950;20:494–504. PubMed Google Scholar 4. Kutlay H, Yavuzer I, Han S, et al. Atypically located pericardial cysts. Ann Thorac Surg 2001;72:2137–2139. PubMed CrossRef Google Scholar 5. [link.springer.com]

Etiology of pericardial cyst6 1.Congenital 2.Inflammatory: Rheumatic pericarditis, Bacterial infection particularly tuberculosis, Echinococcosis 3.Traumatic 4.Post cardiac surgery Table 2 : Etiology of pericardial cyst6. [interventional-cardiology.imedpub.com]

Most are congenital, although several acquired cases with an infectious, inflammatory, or traumatic etiology have been described. [revespcardiol.org]

The main differential diagnosis considered before surgery was hydatid cyst, due to the patient's occupational background, local epidemiology and eosinophilia. The latter could have been related to allergic rhinitis. [elsevier.pt]

Epidemiology A review of collected series reveals that many mediastinal neoplasms and masses vary in incidence and presentation depending on patient age. [emedicine.medscape.com]

Pathophysiology Tumors and cysts of the mediastinum can produce abnormal effects at both systemic and local levels. [emedicine.medscape.com]

Am J Cardiol 55:480–484 CrossRef CAS PubMed Google Scholar Myers RBH, Spodick DH (1999) Constrictive pericarditis: clinical and pathophysiologic chararcteristics. [link.springer.com]

In order to prevent complications, the giant pericardial cyst was excised outside of the pericardium with median sternotomy. [ncbi.nlm.nih.gov]

In order to prevent complications, the giant pericardial cyst was excised outside of the pericardiumwith median sternotomy. [journals.co.za]

Diagnosis is confirmed with computed tomography or magnetic resonance imaging, and surgical treatment is indicated for symptomatic patients. 1, 2 Watchful observation may be feasible for asymptomatic patients, but outcome data are lacking and thus preventive [westjem.com]

The indications for resection of pericardial cysts include large size, symptoms, patient concern, uncertainty of malignant potential, and prevention of the life threatening emergencies. [ctsnet.org]

The indications for resection of pericardial cysts are large size, symptoms, patient concern, uncertainty of malignant potential, and prevention of the life threatening emergencies. [keralamedicaljournal.com]

1. Kar SK, Ganguly T, Dasgupta S, Mitra M, Bhattacharya R. Pericardial Cyst: A Review of Historical Perspective and Current Concept of Diagnosis and Management. Interv Cardiol J. 2015;1:1-8.
2. Patel J, Park C, Michaels J, Rosen S, Kort S. Pericardial cyst: case reports and a literature review. Echocardiography. 2004;21(3):269-272.
3. Cohen AJ, Thompson L, Edwards FH, Bellamy RF. Primary cysts and tumors of the mediastinum. Ann Thorac Surg. 1991;51: 378-384.
4. Braude PD, Falk G, McCaughan BC, Rutland J. Giant pericardial cyst. Aust N Z J Surg. 1990;60(8):640–641.
5. Schweigert M, Dubecz A, Beron M, Ofner D, Stein HJ. The tale of spring water cysts: a historical outline of surgery for congenital pericardial diverticula and cysts. Tex Heart Inst J. 2012;39(3):330-334.
6. Bandeira FC, deSa VP, Moriguti JC, et al. Cardiac tamponade: An unusual complication of pericardial cyst. J Am Soc Echocardiogr. 1996;9(1):108–112.
7. Shiraishi I, Yamagishi M, Kawakita A, Yamamoto Y, Hamaoka K. Acute cardiac tamponade caused by massive hemorrhage from pericardial cyst. Circulation. 2000;101(19):E196-197.
8. Borges AC, Gellert K, Dietel M, Baumann G, Witt C. Acute right-sided heart failure due to hemorrhage into a pericardial cyst. Ann Thorac Surg. 1997;63(3):845-847.
9. Elamin WF, Hannan K. Pericardial cyst: an unusual cause of pneumonia. Cases J. 2008;1: 26.
10. Hoque M, Siripurapu S. Methicillin-resistant Staphylococcus aureus-infected pericardial cyst. Mayo Clin Proc 2005;80:1116.
11. Satur CM, Hsin MK, Dussek JE. Giant pericardial cysts. Ann Thorac Surg. 1996;61: 208-210.
12. Ilhan E, Altin F, Ugur O, et al. An unusual presentation of pericardial cyst: recurrent syncope in a young patient. Cardiol J. 2012;19: 188-191.
13. Mastroroberto P1, Chello M, Bevacqua E, Marchese AR. Pericardial cyst with partial erosion of the superior vena cava. J. Cardiovas Surg. 1996;37(3):323–324.
14. Chopra PS1, Duke DJ, Pellett JR, Rahko PS. Pericardial cyst with partial erosion of the right ventricular wall. Ann Thorac Surg. 1991;51:840–841.
15. Wang ZJ, Reddy GP, Gotway MB, Yeh BM, Hetts SW, Higgins CB. CT and MR imaging of pericardial disease. Radiographics. 2003;23 Spec No:S167-80.
16. Raja A, Walker JR, Sud M, et al. Diagnosis of pericardial cysts using diffusion weighted magnetic resonance imaging: A case series. J Med Case Rep. 2011;5:479.