Surgical View
Abstract
We present the case of a 26 year old, morbidly obese, black female who initially presented in May of 1991 with a one year history of dysphagia. Evaluation revealed a mass in the mediastinum, anterior to the esophagus, which was compressing the esophagus. A left thoracoscopy was performed and a thin-walled cyst containing purulent fluid was drained and the anterior wall was resected. The pathology on the mass wall showed fibrosis and scarring only, consistent with an abscess cavity. The patient had an uneventful recovery. Eighteen months after this surgery she had a recurrence of her dysphagia but a complete evaluation did not reveal any evidence of mediastinal pathology. In August of 1995 she re-presented with dysphagia and a CT scan revealed a recurrence of a mass in the mediastinum anterior to the esophagus.
A repeat left thoracoscopy revealed a recurrence of her previously drained mass. The mass was noted to contain purulent appearing material. Inspection at this procedure revealed a small area of the posterior wall which was discolored. The entire mass was resected off of the esophagus. Pathology revealed the bulk of the cyst wall to consist of fibrotic tissue with chronic inflammation. The discolored area was composed of fibrous connective tissue and fibromuscular tissue with an epithelial lining compatible with respiratory mucosa, consistent with a bronchogenic mediastinal cyst. The patient was discharged on post-op day two and recovered uneventfully.
Origin
Aberrant budding from the primitive foregut Aberrant budding off the tracheobronchial tree after it has arisen as a diverticulum from the foregut
Location
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Paratracheal Carinal
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Paraesophageal
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Also, diaphragmatic, presternal tissue, pericardium, skin, subcutaneous tissue
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Can occur above or below diaphragm
Characteristics
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Round or Oval
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2-10 cm in diameter
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Unilocular
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Usually do not communicate with airway or esophagus
Histology
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Wall
Varying thickness Fibrous tissue interspersed with normal bronchial elements (i.e. bronchial glands, smooth muscle, elastic tissue, cartilage)
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Lining
Smooth Generally psuedostratified columnar epithelium
Symptoms
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Usually asymptomatic
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Newborn may have dyspnea, wheezing, stridor, cyanosis
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Arrhythmias
Diagnosis
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CT Scan -diagnostic modality of choice generally low CT number
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MRI
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Barium swallow
Differential Diagnosis
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Lymphadenopathy
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Cyst of foregut or pericardium
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Pulmonary sequestration
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Tumors
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Teratoma
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Lipoma
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Hamartoma
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Neurogenic tumor
Treatment
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Surgical removal
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Remove asymptomatic cysts because:
Establishes diagnosis Avoids complications Reports of malignancy evolving from benign appearing cysts
Depicting the cyst and its relationship to the diaphragm and the pericardium
Depicting the small amount of respiratory epithelium located posteriorly between the esophagus and pericardium
Showing a high power view of pseudostratified columnar epithelium (Inset is a low power view) corresponding to the surgical view to the left
Bronchogenic mediastinal cysts comprise approximately 6% of mediastinal tumors in large reviews and are generally asymptomatic. Diagnosis can accurately be made with CT scan or MRI. Treatment is by complete resection. Thoracoscopic resection is the treatment of choice and was particularly beneficial in this morbidly obese lady.