Esophageal Duplication Cyst

Pathophysiology

During the fifth to eighth week of fetal life, as the esophagus elongates, its epithelium grows and the cells obliterate the lumen of the esophagus. The esophagus produces secretions, which form into vacuoles. If the vacuoles persist because of failure of proper alignment and coalescence, duplication cysts may be formed. The cyst often occurs on the right because of the elongation of the viscera and dextrorotation of the stomach. Esophageal duplication cysts are more commonly of the cystic form (80%), which has no communication with the lumen of the esophagus. The tubular form, which comprises 20% of esophageal duplication cysts, typically communicates with the esophageal lumen. They vary in size, averaging 4.5 cm for the cystic form, and as large as 25 cm in tubular form. Both esophageal duplication cyst and bronchogenic cyst are lined with ciliated epithelium because of their common embryologic origin. They differ histologically in that bronchogenic duplication cysts contain cartilage, whereas esophageal duplication cysts have two layers of smooth muscle. Esophageal duplication cyst may also contain heterotopic gastric or pancreatic mucosa.

Palmer's pathologic criteria are often used to define an esophageal duplication cyst. The criteria are (1) the lesion should be within or attached to esophageal wall, (2) there should be two layers of smooth muscle (inner circular and outer longitudinal), and (3) the cyst wall lining should contain ciliated epithelium or other cells found in embryologic tissue (squamous, columnar, cuboid, pseudostratified, ciliated). However, there have been noteworthy exceptions in which intraabdominal duplication cysts did not meet the first criterion.

Clinical Presentation

The presentation of an esophageal duplication cyst depends on its size, location, and effect on surrounding structures. It is also related to the age of the patient. For instance, infants and children often present with respiratory distress, cough, or recurrent pneumonias. Although the majority of adults are asymptomatic, presenting symptoms include progressive dysphagia to solids and liquids, epigastric or abdominal pain, and retrosternal chest discomfort. Physical examination is often noncontributory. There are isolated reports of acute, severe abdominal pain in patients who present with cyst perforation or hemorrhage.

There are also rare cases of patients presenting weight loss and lymphadenopathy due to malignancy arising from within the cyst.

Malignant transformation within an esophageal duplication cyst is an extremely rare event, with only a handful of reported cases. The age at presentation ranged widely from 18 to 60 years old, with no gender predominance and variable size from 3 to 10 cm. The clinical presentation of these malignancies varied from an incidental finding to dysphagia, fever, and pain.

The differential diagnosis for a submucosal esophageal lesion includes other nonepithelial tumors such as leiomyoma, gastrointestinal stromal tumor (GIST), sarcoma, lymphoma, lipoma, and other posterior mediastinal masses. For intraabdominal esophageal duplication cyst the differential diagnosis should include pancreatic pseudocyst, dermoid cyst, cystadenoma, and cystadenocarcinoma.

Investigations