Chest (Mediastinal) Cysts
Mediastinal cysts and tumors are relatively common in infants and
children. Although cysts of the mediastinum are often asymptomatic, they
usually require removal. If cysts are symptomatic, they may present with
chest pain, cough, breathing problems, bloody cough or bloody vomiting,
and difficulty swallowing. The various cysts encountered include
bronchogenic cysts, thymic cysts, enterogenous cysts, neurenteric cysts,
dermoid cysts, cystic hygroma, and pericardial cysts.
Diagnostic studies include chest x-rays, CT scan or MRI, dye
(contrast) study of the esophagus, and occasionally ultrasound.
Esophagoscopy (looking into the esophagus), bronchoscopy (looking into
the airways of the lung), and arteriography (injecting dye into the
arteries and taking s-rays) may be useful in selected cases. The exact
preoperative diagnosis is often not possible without either a biopsy or
examination after removal.
Thymic cysts arise from the thymus gland and occur in the front of the
chest. They usually do not cause symptoms. They may have the potential
to undergo cancerous changes. Thymic cysts may present with symptoms
including wheezing and lung infections. They can expand rapidly as a
result of either bleeding within the cyst or infection. In general, when
recognized, thymic cysts should be removed because of these potential
Esophageal Duplication Cysts
Esophageal duplication cysts share a common wall with the normal
esophagus (Figures 1 and 2). These cysts communicate with the inside of
the esophagus in 20% of cases. Neck or chest vertebral abnormalities
often are associated with esophageal duplication cysts. Very rarely,
these cysts may attach to or communicate with the spinal canal or
occasionally to the dura (lining of the spinal cord) and are then
referred to as neurenteric cysts. Patients with neurenteric cysts may
present with pain or neurologic findings. They are at risk for
developing complications such as paraplegia (paralysis of the lower
body) and meningitis. In addition, it is common (10% to 15%) for an
esophageal duplication cyst to be accompanied by an intestinal
duplication in the abdomen.
Figure 1. Computed tomography scan shows an esophageal
duplication extending into the right chest from the mediastinum
Figure 2: An esophageal duplication cyst (arrows) during removal from
the chest. Black arrowhead points to lung.
Esophageal duplication cysts may also
extend down through the diaphragm to end blindly in the abdomen or may
communicate with the small intestine (Figure 2).
Figure 3. Diagram of duplication of the esophagus
communicating with the jejunum (beginning of the small intestine).
Rarely, multiple esophageal duplication cysts have been observed. The
presence of abnormal stomach tissue within the cyst can result in
ulcers, bleeding, or rupture of the cyst or nearby intestinal tissue.
Duplication cysts may enlarge suddenly and push on the lungs or normal
esophagus causing breathing problems or difficulty swallowing. For these
reasons, removal of the cyst is recommended when they are found.
Patients with neurenteric cysts may require the expertise of a pediatric
surgeon and neurosurgeon for removal.
Cystic hygromas are thin-walled, cysts containing lymphatic fluid. Most
patients are born with these cysts. They most commonly arise in the
neck. In 10% to 15% of cases, the cyst extends into the chest from the
neck (Figure 4). Rarely, they may arise primarily within the chest.
Bleeding into the cyst or infection may cause the cysts to enlarge
rapidly and result in pressure on the airway and sudden onset of
problems with breathing. This may require an urgent operation.
Figure 4. Removal of a lymphangioma of the neck. The multiple
fluid-filled “cysts” typical of a lymphangioma or cystic
hygroma can be seen within the incision.
The pericardium is the sac surrounding the heart. Pericardial cysts most
often appear on a routine chest x-ray and do not cause problems. They
are usually on the right side of the heart. These cysts are thin walled,
contain clear fluid, and may be removed easily to make sure that they
are not cancerous.
Dermoid cysts are some of the largest chest tumors seen in children. The
typical dermoid cyst is thick-walled, containing various parts of skin,
hair, occasionally teeth, and caseous (cheesy) material. The tumors are
usually found in the front of the chest, but rarely are located within
the pericardium (the sac that surrounds the heart). Dermoid cysts rarely
become cancerous. Removal of dermoid cysts is warranted because of the
risk of infection and potential rupture. When that happens, the patient
occasionally may present by coughing up hair.
Bronchogenic cysts are located in the middle of the chest. These cysts
originate before the airways of the lungs are formed in the fetus and
persist after birth. They are usually located close to the first
branching of the windpipe (trachea) known as carina (Figure 5).
Figure 5. Computed tomography scan shows the typical finding
of a bronchogenic cyst (arrows) located in the region of the carina
partially narrowing the right main stem bronchus.
Bronchogenic cysts form when epithelial cells from the developing
trachea and lung are pinched off and become separated from the airways.
Bronchogenic cysts are usually, but not always, outside of the lung
(Figure 6). They do not communicate with the normal airways. In
addition, bronchogenic cysts do not contain air sacs (alveoli).
Under the microscope, bronchogenic cysts are thin walled and often
contain cartilage and sometimes glands from the airways. These cysts
often have no symptoms and may be noted as an unexpected finding on a
chest x-ray. Bronchogenic cysts in the area of the carina can compress
the trachea, however, resulting in breathing problems in newborns.
They may be detected on chest x-ray or CT scan of the chest.
Symptomatic cysts should be removed. Asymptomatic cysts should also be
removed because of the risk of infection. A rare case of cancer in a
bronchogenic cyst occurring in an 8-year-old girl has been reported.
Most bronchogenic cysts can be removed safely using thoracoscopic
techniques. Thoracoscopy may be contraindicated in children with cysts
under the carina. In some cases, it is extremely difficult to separate
the wall of the cyst from the normal airway. Near-complete removal and
leaving the attached portion of the cyst wall on the airway is
reasonable treatment and has not been associated with recurrence.
Figure 6: This photo shows a bronchogenic cyst (surrounds by
arrows) as it is being removed from the chest. The lung is demonstrated
by the arrowhead.
Michel JR, Revillon Y, Montupet P, et al: Thoracoscopic treatment of
mediastinal cysts in children. J Pediatr Surg 33:1745-1748, 1998.
This excellent article describes the efficacy of thoracoscopic excision
of mediastinal cysts and its contraindications.
Philippart AI, Farmer DL: Benign mediastinal cysts and
tumors. In O’Neill JA Jr, Rowe MI, Grosfeld JL, et al (eds):
Pediatric Surgery, 5th ed. St Louis, Mosby, 1998, pp 839-851.
This chapter presents an up-to-date, in-depth review of all of the
various considerations related to mediastinal masses.
Rodgers BM, McGahren ED: Mediastinum and Pleura. In
Oldham KT, Colombani PM, Foglia RP, Skinner, MA (eds): Principles and
Practice of Pediatric Surgery Philadelphia, Lippincott Williams &
Wilkins, 2005, pp 929-949.
Articles and graphics adapted from O'Neill: Principles of Pediatric
Surgery. © 2003, Elsevier.