A pericardial cyst is an uncommon benign dilatation of the pericardial sac surrounding the heart. It can lead to symptoms by compressing nearby structures, but is usually asymptomatic. [1] Pericardial cysts can be congenital or acquired, and they are typically diagnosed with radiologic imaging. [1] [2] [3] Management of pericardial cysts can include follow-up imaging, percutaneous aspiration, or surgical resection. [1] [2] [3]
Pericardial cysts most often are asymptomatic, with 50 to 75% of patients experiencing no symptoms. [1] [2] The presentation of symptomatic cysts depends on the cyst location and effects on nearby structures, including the heart, lungs, and esophagus. [2] [3] Symptoms can include chest pain, cough, shortness of breath, palpitations, syncope, recurrent pneumonia, congestive heart failure, difficulty swallowing, and weight loss. [1] [2] [3]
Pericardial cysts can be congenital or acquired, with the majority being congenital. [2] [3] Congenital pericardial cysts happen due to an abnormality in the development of the pericardial sac that creates a bulge which is walled off to form a cyst. [1] [3] Acquired pericardial cysts can be caused by inflammation from surgery, pericarditis, trauma, echinococcosis, tuberculosis, metastasis, or hemodialysis. [2] [3] The inflammation can lead to a walled-off pocket of fluid that is a pericardial cyst. [3]
Since pericardial cysts are often asymptomatic, the most common diagnosis is through incidental finding on a chest x-ray. [1] [2] Differentiation of pericardial cysts from diverticula is usually impossible as both the lesions have similar radiological appearance. The lone differentiating feature is the presence of communicating tract between pericardium and the cyst cavity in the diverticula, unlike the fully walled off pericardial cyst. [4] [5] When patients have symptoms, transthoracic echocardiogram is one of the first tests used to look for a pericardial cyst. [3] CT or MRI may also be used to diagnose pericardial cysts. [4] [6] [7] On CT and MRI a pericardial cyst will commonly appear as a round, fluid-filled structure surrounded by thin walls. [4] [6] [7] Diagnosis of a pericardial cyst can also be made before birth using ultrasound. [2]
The differential diagnosis for a suspected pericardial cyst includes a bronchial cyst, pericardial effusion, teratoma, lymphangioma, pericardial fat, congenital diaphragmatic hernia, neuroenteric cyst, and congenital cyst from the primitive foregut. [1] [2] [3]
Pericardial cysts that are small and cause no symptoms can be followed with repeat imaging through echocardiogram, CT, or MRI to assess for changes. [1] [2] Pericardial cysts that are large or cause symptoms may be candidates for percutaneous aspiration, ethanol sclerosis, or surgery. [1] [2] [3] Percutaneous aspiration removes the fluid from inside the cyst, and ethanol sclerosis uses the injection of ethanol into the cyst after aspiration to decrease the likelihood of cyst recurrence. [2] [3] Percutaneous aspiration with ethanol sclerosis is typically the first treatment for pericardial cyst that requires management. [2] [3] Surgery can remove a pericardial cyst through a thoracotomy, sternotomy, mediastinoscopy, or video-assisted thoracic surgery. [1] [2] The type of surgery is chosen based on the size and location of the pericardial cyst. [2]
With most pericardial cysts having no symptoms, the prognosis is very good. [1] The cysts can resolve without intervention. [1] [3] If percutaneous aspiration is performed, the recurrence rate of pericardial cysts is about 30-33%. [1] [3] Although pericardial cysts are benign, the location of cysts can rarely cause life-threatening emergencies by compressing the heart or lungs. [1] [2]
Pericardial cysts have an incidence of 1 in 100,000. [2] [7] Pericardial cysts make up 6-7% of all mediastinal masses. [2] [3] They can present at any age, but are most commonly diagnosed between the third and fifth decade of life. [2] [3] Females and males have approximately equal incidences of pericardial cysts. [2]
Pericardial cysts were first reported on during autopsies in the 19th century by pathologists. [2] [8] As the field of radiology progressed, pericardial cysts could be identified in living patients. [2] [8] In 1931, the first surgical resection of a pericardial cyst was performed by Otto Pickhardt at Lenox Hill Hospital in New York using a thoracoscopy. [2] [8] In 1943, Greenfield and his colleagues coined the term "spring water cysts" for pericardial cysts since the cysts contain clear fluid. [2] [8]
The pericardium, also called pericardial sac, is a double-walled sac containing the heart and the roots of the great vessels. It has two layers, an outer layer made of strong inelastic connective tissue, and an inner layer made of serous membrane. It encloses the pericardial cavity, which contains pericardial fluid, and defines the middle mediastinum. It separates the heart from interference of other structures, protects it against infection and blunt trauma, and lubricates the heart's movements.
Cardiac tamponade, also known as pericardial tamponade, is a compression of the heart due to pericardial effusion. Onset may be rapid or gradual. Symptoms typically include those of obstructive shock including shortness of breath, weakness, lightheadedness, and cough. Other symptoms may relate to the underlying cause.
Aneurysm of the aortic sinus, also known as the sinus of Valsalva, is a rare abnormality of the aorta, the largest artery in the body. The aorta normally has three small pouches that sit directly above the aortic valve, and an aneurysm of one of these sinuses is a thin-walled swelling. Aneurysms may affect the right (65–85%), non-coronary (10–30%), or rarely the left coronary sinus. These aneurysms may not cause any symptoms but if large can cause shortness of breath, palpitations or blackouts. Aortic sinus aneurysms can burst or rupture into adjacent cardiac chambers, which can lead to heart failure if untreated.
A pericardial effusion is an abnormal accumulation of fluid in the pericardial cavity. The pericardium is a two-part membrane surrounding the heart: the outer fibrous connective membrane and an inner two-layered serous membrane. The two layers of the serous membrane enclose the pericardial cavity between them. This pericardial space contains a small amount of pericardial fluid, normally 15-50 mL in volume. The pericardium, specifically the pericardial fluid provides lubrication, maintains the anatomic position of the heart in the chest (levocardia), and also serves as a barrier to protect the heart from infection and inflammation in adjacent tissues and organs.
Aberrant subclavian artery, or aberrant subclavian artery syndrome, is a rare anatomical variant of the origin of the right or left subclavian artery. This abnormality is the most common congenital vascular anomaly of the aortic arch, occurring in approximately 1% of individuals.
Angiomyolipomas are the most common benign tumour of the kidney. Although regarded as benign, angiomyolipomas may grow such that kidney function is impaired or the blood vessels may dilate and burst, leading to bleeding.
Lymphangiomatosis is a condition where a lymphangioma is not present in a single localised mass, but in a widespread or multifocal manner. It is a rare type of tumor which results from an abnormal development of the lymphatic system.
Primary tumors of the heart are extremely rare tumors that arise from the normal tissues that make up the heart. The incidence of primary cardiac tumors has been found to be approximately 0.02%. This is in contrast to secondary tumors of the heart, which are typically either metastatic from another part of the body, or infiltrate the heart via direct extension from the surrounding tissues. Metastatic tumors to the heart are about 20 times more common than primary cardiac tumors.
Degloving occurs when skin and the fat below it, the subcutaneous tissue, are torn away from the underlying anatomical structures they are normally attached to. Normally the subcutaneous tissue layer is attached to the fibrous layer that covers muscles known as deep fascia.
Thyroid nodules are nodules which commonly arise within an otherwise normal thyroid gland. They may be hyperplastic or tumorous, but only a small percentage of thyroid tumors are malignant. Small, asymptomatic nodules are common, and often go unnoticed. Nodules that grow larger or produce symptoms may eventually need medical care. A goitre may have one nodule – uninodular, multiple nodules – multinodular, or be diffuse.
Tuberculous pericarditis is a form of pericarditis. It is a condition in which the pericardium surrounding the heart is infected by the bacterial species Mycobacterium tuberculosis. Tuberculous pericarditis accounts for a significant percentage of presentations of tuberculosis worldwide. The condition has four stages of disease which manifests with clinical presentations ranging from acute pericarditis to overt heart failure. Tuberculous pericarditis is an under-diagnosed condition. Diagnosis often requires a range of diagnostic tools, including pericardiocentesis, biochemical tests, and imaging. Treatment of this disease is similar to treatment of pulmonary tuberculosis. Alternative treatment options to reduce cardiac complications are also available.
Tarlov cysts, are type II innervated meningeal cysts, cerebrospinal-fluid-filled (CSF) sacs most frequently located in the spinal canal of the sacral region of the spinal cord (S1–S5) and much less often in the cervical, thoracic or lumbar spine. They can be distinguished from other meningeal cysts by their nerve-fiber-filled walls. Tarlov cysts are defined as cysts formed within the nerve-root sheath at the dorsal root ganglion. The etiology of these cysts is not well understood; some current theories explaining this phenomenon have not yet been tested or challenged but include increased pressure in CSF, filling of congenital cysts with one-way valves, and/or inflammation in response to trauma and disease. They are named for American neurosurgeon Isadore Tarlov, who described them in 1938.
Theca lutein cyst is a type of bilateral functional ovarian cyst filled with clear, straw-colored fluid. These cysts result from exaggerated physiological stimulation due to elevated levels of beta-human chorionic gonadotropin (beta-hCG) or hypersensitivity to beta-hCG. On ultrasound and MRI, theca lutein cysts appear in multiples on ovaries that are enlarged.
Ectopic thymus is a condition where thymus tissue is found in an abnormal location (ectopia). It usually does not cause symptoms, but may leads to a mass in the neck that may compress the trachea and the esophagus. It is thought to be the result of either a failure of descent or a failure of involution of normal thymus tissue. It may be diagnosed with radiology, such as an ultrasound or magnetic resonance imaging. If it causes illness, surgery can be used to remove it. Recurrence after surgery is very unlikely.
A cavernous liver hemangioma or hepatic hemangioma is a benign tumor of the liver composed of large vascular spaces lined by monolayer hepatic endothelial cells. It is the most common benign liver tumour, and is usually asymptomatic and diagnosed incidentally on radiological imaging or during laparotomy for other intra-abdominal issues. Liver hemangiomas are thought to be congenital in origin with an incidence rate of 0.4 – 7.3% as reported in autopsy series.
A urethral diverticulum is a condition where the urethra or the periurethral glands push into the connective tissue layers (fascia) that surround it.
Mediastinal shift is an abnormal movement of the mediastinal structures toward one side of the chest cavity. A shift indicates a severe imbalance of pressures inside the chest. Mediastinal shifts are generally caused by increased lung volume, decreased lung volume, or abnormalities in the pleural space. Additionally, masses inside the mediastinum or musculoskeletal abnormalities can also lead to abnormal mediastinal arrangement. Typically, these shifts are observed on x-ray but also on computed tomography (CT) or magnetic resonance imaging (MRI). On chest x-ray, tracheal deviation, or movement of the trachea away from its midline position can be used as a sign of a shift. Other structures, like the heart, can also be used as reference points. Below are examples of pathologies that can cause a mediastinal shift and their appearance.
A biloma is a circumscribed abdominal collection of bile outside the biliary tree. It occurs when there is excess bile in the abdominal cavity. It can occur during or after a bile leak. There is an increased chance of a person developing biloma after having a gallbladder removal surgery, known as laparoscopic cholecystectomy. This procedure can be complicated by biloma with incidence of 0.3–2%. Other causes are liver biopsy, abdominal trauma, and, rarely, spontaneous perforation. The formation of biloma does not occur frequently. Biliary fistulas are also caused by injury to the bile duct and can result in the formation of bile leaks. Biliary fistulas are abnormal communications between organs and the biliary tract. Once diagnosed, they usually require drainage. The term "biloma" was first coined in 1979 by Gould and Patel. They discovered it in a case with extrahepatic bile leakage. The cause of this was trauma to the upper right quadrant of the abdomen. Originally, biloma was described as an "encapsulated collection" of extrahepatic bile. Biloma is now described as extrabiliary collections of bile that can be either intrahepatic or extrahepatic. The most common cause of biloma is trauma to the liver. There are other causes such as abdominal surgery, endoscopic surgery and percutaneous catheter drainage. Injury and abdominal trauma can cause damage to the biliary tree. The biliary tree is a system of vessels that direct secreations from the liver, gallbladder, and pancreas through a series of ducts into the duodenum. This can result in a bile leak which is a common cause of the formation of biloma. It is possible for biloma to be associated with mortality, though it is not common. Bile leaks occur in about one percent of causes.
Raghib syndrome is rare a congenital heart defect where the left superior vena cava (LSVC) is draining into the left atrium in addition to an absent coronary sinus and an atrial septal defect. This can be considered a dangerous heart condition because it puts the individual at a high risk of stroke. Other defects that are often associated with Raghib syndrome can include ventricular septal defects, enlargement of the tricuspid annulus, and pulmonary stenosis. While this is considered an extremely rare developmental complex, cases regarding a persistent left superior vena cava (PLSVC) are relatively common among congenital heart defects. It is also important to note that the PLSVC often drains into the right atrium, and only drains into the left atrium in approximately 10 to 20% of individuals with the defect.
Purulent pericarditis refers to localized inflammation in the setting of infection of the pericardial sac surrounding the heart. In contrast to other causes of pericarditis which may have a viral etiology, purulent pericarditis refers specifically to bacterial or fungal infection of the pericardial sac. Clinical etiologies of purulent pericarditis may include recent surgery, adjacent infection, trauma, or even primary infection. The onset of purulent pericarditis is usually acute, with most individuals presenting to a medical facility approximately 3 days following the onset of symptoms.