Esophageal atresia

Pathologic Diagnosis: Residual Tracheobronchial Remnants, Consistent With the History of TEF

Congenital TEF and esophageal atresia (EA) are relatively common congenital anomalies with an incidence of 1 in 3000 to 3500 live births.1 The esophagus develops as an extension of the superior portion of the primitive foregut very early in the embryonic process.2 When the embryo is approximately 4 weeks old, the respiratory diverticulum (lung bud) appears as an outgrowth from the ventral wall of the foregut.1 Initially, the lung is in open communication with the foregut. When the diverticulum expands in a caudal direction, however, it becomes separated from the foregut by development of 2 longitudinal ridges, the esophagotracheal ridges.1 Subsequently, when these ridges are fused to form a septum (esophagotracheal septum), the foregut is divided into dorsal and ventral portions, forming the esophagus and trachea, respectively.1 Abnormalities in partitioning of the esophagus and trachea result in EA, a condition usually associated with TEF.1,2 The 5 major varieties of TEF and EA with their frequency are as follows: EA with distal TEF, 85%; EA with no TEF, 8%; H-type TEF, 4%; EA with proximal TEF, 2%; and EA with proximal and distal TEF, 1%.2,3 Forty percent of patients with TEF have associated anomalies, most frequently of a cardiovascular nature. These anomalies include patent ductus arteriosus, vascular ring, and coarctation of aorta. Other gastrointestinal malformations are also increased. Polyhydramnios and excessive salivation are early clinical manifestations of TEF, followed by choking, coughing, and cyanosis after the first feeding. Primary surgical repair is the treatment of choice when the infant's condition is suitable.2 Keys of the operative technique are careful division of the fistula with closure of the tracheal opening and adequate mobilization of the upper esophagus to permit anastomosis without tension.4 Postoperative strictures are not infrequent (10%-20%). They become clinically apparent with dysphagia to solid food at any time from the postoperative period to months or years later. Even after repair, esophageal motility and the anatomy of the gastroesophageal junction are altered, potentially leading to gastroesophageal reflux. An antireflux procedure, such as a Nissen fundoplication, is used to prevent further reflux.5

A 27-year-old, white woman had undergone a surgical repair procedure for a congenital tracheoesophageal fistula (TEF) immediately following birth. At the age of 4 years, she underwent a fundoplication for gastroesophageal reflux disease (GERD), followed by multiple endoscopie dilations of the lower esophageal sphincter (LES). She continued to complain of persistent dysphagia, especially when consuming large particles of food, which worsened during the months before her last admission. Manometric studies showed an increase in LES pressure and decreased peristaltic movements of the esophagus. During this admission, a near total vagal-sparing esophagectomy with a colonic interposition was performed.

The specimen received in the surgical pathology laboratory consisted of the esophagus and proximal stomach. The esophagus measured 9.0 cm in length. A minimal amount of periesophageal tissue was present. Evidence of a remote surgical anastomosis was noted. The esophagus was lined by the usual gray-white mucosa. No focal abnormality was seen during the gross examination. Microscopic examination of the distal esophagus revealed GERD, characterized by the presence of cardiac-type metaplasia (Figure 1). No specialized columnar cells were seen. Proximal to this, plates of mature cartilage and acini of minor salivary glands were seen within the muscularis (Figures 2 through 4). Branchial cleft-like cysts were also seen (Figure 4).

What is your diagnosis?

There is a very high incidence of tracheobronchial remnants in the lower esophageal segment in the form of dilated epithelial clusters of seromucous glands and cartilage. In the normal esophagus, only neutral and sulfomucin glands are identified. In a study by Dutta et al,6 which included a series of 65 patients, 10 patients had a combination of sialomucins and sulfomucins in the esophagus, which were more abundant in one patient, a condition not seen in the normal esophagus. Therefore, patients with TEF and AE may have both sialomucin and sulfomucin glands in the esophagus. These findings are often associated with irregularity of the smooth muscle fibers. Some reports have suggested that this lack of normal muscle coat and presence of tracheobronchial remnants may be responsible for the abnormal motility noted in these patients after successful primary anastomosis.6 These patients present with esophageal strictures that do not respond to dilations but have a dramatic response to resection of the stricture. These strictures are present in the lower esophagus and are away from the area of the fistula and hence the anastomosis.6

References

1. Sadler TW. Respiratory system. In: Sadler TW, ed. Langman's Medical Embryology. 7th ed. Baltimore, Md: Williams & Wilkins; 1995;232-241.

2. Kirschner BS, Black DD. Gastrointestinal tract. In: Behrman RE, Kliegman RM, eds. Nelson Essentials of Pediatrics. 2nd ed. Philadelphia, Pa: WB Saunders; 1994:395-432.

3. Crawford JM. The gastrointestinal tract. In: Cotran RS, Kumar V, Collins T, eds. Robbins Pathologic Basis of Disease. 6th ed. Philadelphia, Pa: WB Saunders; 1999:775-843.

4. Myers NA. Oesophageal atresia: the epitome of modern surgery. Ann R Coll Surg Engl. 1974;54:277-287.

5. Guzzetta PC, Anderson KD, Altman RP, et al. Pediatric surgery. In: Schwanz Sl, ed. Principles of Surgery. 7th ed. New York, NY: McGraw-Hill; 1998:1681-1724.

6. Dutta HK, Mathur M, Bhatnagar V. A histopathological study of esophageal atresia and tracheoesophageal fistula. J Pediatr Surg. 2000;35:438-441.

Neda A. Moatamed, MD; Milton T. Kiyabu, MD

Accepted for publication June 20, 2003.

From the Department of Pathology, University of Southern California School of Medicine, Los Angeles.

Reprints: Neda A. Moatamed, MD, LAC/USC Medical Center, Department of Pathology, #2900, 1200 N State St, Los Angeles, CA 90033 (e-mail: moatamed@ucla.edu).

Copyright College of American Pathologists Nov 2003
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