28: Overview: Anatomy and Pathophysiology of Benign Esophageal Disease

The term “esophagus” derives from the Greek root “oisein” (to carry) and “phagos” (to eat). The esophagus' intricate components perform in symphony to provide a muscular conduit between the pharynx and stomach. Even small deviations in structure can lead to dysfunction. Benign esophageal lesions can obstruct the esophageal lumen and produce symptoms. This chapter discusses esophageal development and anatomy as well as the pathophysiology of benign esophageal diseases. Chapter 29 details the surgical and endoscopic approaches to these diseases. Motility disorders and congenital esophageal diseases are discussed in more detail in Chapters 33 and 51, respectively.

The esophagus and trachea both form from a medial ventral diverticulum arising from the primordial foregut at approximately day 22 or 23 of fetal development (Fig. 28-1). The foregut divides into trachea and esophagus during week 4. The stomach bud forms posteriorly shortly thereafter. Both the trachea and esophagus elongate between days 23 and 34 or 36. It is thought that esophageal lengthening occurs by ascent of the pharynx rather than descent of the stomach. By approximately day 36, the trachea and esophagus have completely separated.¹

The esophageal wall is derived from both endoderm and mesoderm. The endoderm forms the epithelium and glands, whereas the mesoderm eventually forms the muscular layers, connective tissue, and angioblasts. During the seventh and eighth weeks of development, the esophageal epithelium proliferates to fill the lumen, leaving only small irregular channels open. These channels grow to form vacuoles, which then coalesce to create one lumen by the 10th week of gestation (Fig. 28-2). Ciliated epithelium initially lines the embryological esophagus, but it is replaced by the fourth month of gestation by stratified squamous epithelium. By the sixth week, the mesenchymal circular muscular coat forms, and the splanchnic mesenchyme surrounds the esophagus and trachea. The splanchnic mesenchyme enables the formation of the smooth muscle of the lower esophagus. The longitudinal musculature forms during weeks 9 through 12, and the muscularis mucosa forms by week 16. Blood vessels start to enter the esophageal wall in week 28, but the lymphatic capillaries do not form until the third to fourth month of gestation.¹

Congenital anomalies of the esophagus occur in 1 in 3500 births and typically are the result of a genetic defect or maternal event. They are more common in premature infants, and 60% are associated with other congenital anomalies, including VACTERL syndrome (associated vertebral, anal, cardiac, tracheal, esophageal, renal, and limb congenital anomalies).² For further information regarding congenital anomalies of the esophagus, including atresia, stenosis, clefts, and tracheoesophageal fistula, see Chapter 51.

Esophageal terminology can be classified by function, anatomy, or surgical divisions. Anatomically, the esophagus is divided into cervical, thoracic, and abdominal portions. Surgeons further classify esophageal anatomy based on therapeutic approach and adjacent structures as cervical, proximal, middle, distal thoracic, and abdominal.

The esophagus ranges from 21 to 34 cm in length from the cricopharyngeus to the lower esophageal sphincter (LES), with an average length of 23 cm in females and 28 cm in males. The cervical esophagus ranges from 3 to 5 cm in length, the thoracic portion 18 to 22 cm, and the abdominal portion 3 to 5 cm. The distance from the incisors to the cricoid cartilage is 13 cm.³

Nonkeratinizing, stratified squamous epithelium lines most of the esophageal lumen. This mucosa contains only alveolar serous glands, which are small, tubular mucus glands originating from the submucosa. In the terminal esophagus, cardiac glands, much like those found in the stomach, project through the epithelium to form papillae. Endoscopically, the transition between the esophageal squamous mucosa and the columnar gastric mucosa starts as four-to-six pink tongues projecting up through the paler distal esophagus at what is known as the “Z-line” just proximal to the esophagogastric junction. Replacement of the distal esophageal squamous mucosa by columnar epithelium is diagnostic of Barrett esophagus, a premalignant condition.³ For further information on Barrett esophagus, see Chapter 41.

The lamina propria mucosa lies deep to the mucosa and consists of an areolar, elastic, and collagenous network of fibers that contains small blood vessels, follicles, and mucus glands. The muscularis mucosa is a thin layer of smooth muscular bundles. The submucosa consists of loose areolar connective tissue and elastic and collagen fibers with numerous blood vessels, lymphatics, nerves (including Meissner plexus), and deep mucus glands (Fig. 28-3).

The pharyngeal and esophageal muscles coordinate to form coordinated contractions to make swallowing and speech possible. Pharyngeal muscle is striated, whereas the esophagus transitions to more smooth muscle as it descends past the level of the carina and the lower two-thirds of the esophagus. The tunica muscularis is composed of oblique muscle fibers in a single layer in the pharynx, but two layers throughout the esophagus: a longitudinal outer layer and circular inner layer. The circular layer is an extension of the cricopharyngeus muscle.³

The upper esophageal sphincter (UES) acts as the gatekeeper for entry of a food bolus from the pharynx to the esophagus during swallowing. The posterior cricoid cartilage forms the anterior wall of the UES, and a muscular sling of the lower inferior pharyngeal constrictor forms the posterior UES. This sphincter functions to prevent esophageal distension during respiration and to prevent reflux, as it remains in a tonic state of contraction with 30 to 142 mm Hg of pressure between episodes of swallowing.

The LES does not have anatomy as discrete as the UES. The LES is composed in part from a thickening of the circular esophageal fibers that superimpose on each other approximately 3 cm from the gastroesophageal junction. It is not macroscopically or grossly detectable. The LES, in conjunction with the diaphragmatic crura, angle of His, and intra-abdominal length of esophagus, provides a tonic pressure of 14.5 to 34 mm Hg to prevent reflux.³ Liebermann-Meffert⁴ described short transverse clasp fibers and oblique sling fibers in cadavers that curve around the greater curve that aid in the sphincter effect and help account for the asymmetric anatomy of the LES. For more information regarding the pathophysiology of the esophageal sphincters, see Chapter 33.

Only loose adventitia adheres the esophagus to its surrounding mediastinum, as it has no serosa or mesentery. These loose attachments allow for considerable cephalocaudal movement during respiration.

Arterial Supply

The esophagus receives arterial blood from multiple sources as it courses through the neck, chest, and abdomen.

The superior thyroid artery gives off smaller arteries that supply the UES and pharynx. The inferior thyroid arteries supply the cervical esophagus. They give off 2 to 3 cm branches called tracheoesophageal arteries that travel inferiorly and medially on each side. The tracheoesophageal arteries subdivide into tracheal and esophageal branches, which in turn subdivide several more times before they eventually enter the esophageal wall.³

The thoracic esophagus derives its blood supply from the superior and inferior thyroid arteries superiorly and the aorta inferiorly. Both the tracheobronchial arteries and the bronchoesophageal artery originate from the aortic arch and further subdivide to provide branches to the trachea. The proper aortic esophageal arteries are unpaired and arise from the descending aorta.³

The abdominal esophagus is supplied by the left gastric artery, ascending branches from the left phrenic artery, and the splenic artery. The splenic artery delivers arterial blood to the posterior and left lateral distal esophagus. Branches from both extend beyond the diaphragmatic hiatus. The repetitive branching of the arterial supply eventually forms a rich submucosal arterial plexus that allows for ligation of extramural vessels without compromising the underlying esophagus (Fig. 28-4).

Venous Drainage

A submucosal venous plexus drains blood from the subepithelial venous network. This plexus then empties into communicating veins that traverse the muscular wall along with the perforating arteries. The superior esophagus drains into the internal jugular veins or the azygos or hemiazygos veins. The inferior veins drain into the left gastric and splenic veins. There are no valves in the esophageal venous system.³

Lymphatic Drainage

The lymphatic system of the esophagus is poorly described. Lymph from the thoracic esophagus likely drains to paratracheal, tracheobronchial bifurcation, juxtaesophageal, and intra-aorticoesophageal nodes. The abdominal esophagus likely drains to superior gastric, pericardiac, and inferior diaphragmatic nodes. All areas of the esophageal lymph system eventually empty into the thoracic duct. Lymphatic channels are more abundant as longitudinal submucosal channels than in the muscular layers.³

Innervation

The visceral autonomic nervous system innervates the esophagus, pharynx, and larynx. The sympathetic efferent pathways cause vasoconstriction, sphincter contraction, and relaxation of the muscular wall via the cervical and thoracic sympathetic chains. The parasympathetic nervous system increases glandular and peristaltic activity via the vagus (cranial nerve X). The vagus also carries somatic and visceral sensory and skeletal motor fibers to the esophagus. The superior laryngeal nerve mainly has a secretory and sensory function, but it also supplies motor branches to the larynx and cricopharyngeus muscle, which controls the timbre of the voice.³

Benign esophageal neoplasms are rare lesions, most occurring in less than 0.5% of the population on autopsy. A review of 20,000 autopsies in 1962 found only 90 benign esophageal tumors, or a prevalence of 0.45%.⁵ The majority of benign esophageal tumors do not cause symptoms unless they become large enough to obstruct the esophageal lumen or impinge on surrounding structures. Mucosal lesions are more likely to present with symptoms, as they are more likely to obstruct the lumen. One must keep in mind a broad differential diagnosis when evaluating these patients, as these lesions can create mechanical obstruction and symptoms common to many other esophageal diseases (Table 28-1). Adult patients with cancer, gastroesophageal reflux, motility disorders, esophagitis, or even psychiatric illness can have similar presentations to these benign lesions.

These lesions are typically found incidentally on imaging or on endoscopy and typically do not warrant resection unless they mechanically compress mediastinal structures. Generally, removal is recommended for patients with symptoms or larger lesions.

Papillomas

Esophageal papillomas are small (typically subcentimeter) benign sessile lesions arising from the lamina propria in the distal esophagus.⁶ Histologically, they have finger-like projections of squamous-lined epithelium over a core of connective tissue. Endoscopically, they appear as pale exophytic, wart-like lesions that can be mistaken for verrucous squamous cell carcinoma, granulation tissue, or papillary leukoplakia. They occur most often in the fifth decade of life.⁷ They rarely cause symptoms, but large lesions can cause dysphagia.

Differing theories exist regarding the origin of esophageal papillomas. A theory of local inflammation giving rise to papillomas is supported by an association with reflux, esophagitis, and mucosal irritants as well as the distal location of papillomas.⁸ Animal studies have shown a causative relationship between chemical mucosal irritation and the development of esophageal papillomas.⁹ Some evidence points to a role of the human papilloma virus (HPV) in the development of esophageal papillomas based on varying reports on the prevalence of HPV in patients with esophageal papillomas. Although HPV has been linked to laryngeal and cervical cancers, there is no conclusive evidence for a relationship between HPV and esophageal malignancy (Fig. 28-5).

Adenomas

Esophageal adenomas are hyperplastic epithelial cells in a polypoid configuration, similar to adenomas elsewhere in the gastrointestinal tract. Esophageal adenomas arise almost exclusively in the setting of Barrett esophagus and are more likely a polypoid dysplastic tissue than purely adenomatous tissue. Isolated esophageal adenomas are exceedingly rare, with only a handful of cases reported in the literature. An association of these lesions with concomitant adenocarcinoma further supports their relationship to Barrett esophagus. Given this association to cancer, these lesions should be treated as premalignant and should be removed.¹⁰ They appear as polypoid mucosal lesions and should be removed endoscopically. If found in the setting of normal esophageal mucosa, multiple biopsy specimens of the surrounding tissue should be taken to evaluate for evidence of metaplasia. For further detail regarding the management of Barrett esophagus and the pathology of esophageal cancer, see Chapters 41 and 10, respectively.

Inflammatory Polyps

Inflammatory polyps are edematous folds of gastric mucosa occurring at the gastroesophageal junction. These benign lesions are the result of gastroesophageal reflux. Microscopically, they appear as inflamed gastric mucosa with plasma cells, eosinophils, fibroblasts, and multinucleated giant cells surrounding the epithelium. They typically resolve with treatment of reflux and do not need to be resected.¹¹

Fibrovascular Polyps

Fibrovascular polyps represent a group of fibrous benign lesions consisting of fibrous, vascular, and adipose tissues covered by normal gastrointestinal submucosa. They are extremely rare and represent only 0.5% to 1% of all benign esophageal lesions.¹² The group includes lipomas, myomas, fibromas, and fibrolipomas. They occur more in the proximal esophagus, where large lesions (as large as 20 cm) have been reported to cause dysphagia, cough, nausea, vomiting, and even asphyxiation.¹³ An endoscopic ultrasound can diagnose a polyp with a large feeding vessel, which, if present, would preclude endoscopic resection. An endoscopist can successfully remove symptomatic lesions if they have a visible stalk and do not have a large feeding vessel.¹⁴

Granular Cell Tumors

Granular cell tumors can arise from skin, breast, tongue, and gastrointestinal tract. They are rare tumors—only 10% occur in the gastrointestinal tract and 65% of those occur in the esophagus. They occur most commonly in men ages 45 to 60 years old. They are usually asymptomatic, with approximately one-third of diagnosed patients reporting dysphagia.¹⁵ Granular cell tumors are neural in origin and likely arise from Schwann cells. Microscopically, they appear as nests of cells with pyknotic nuclei, abundant eosinophilic granular cytoplasm, and strong S-100 positivity.⁶ They appear pale or yellow on endoscopy and feel firm or rubbery when palpated with forceps (Fig. 28-6).

Unlike most other benign lesions discussed in this chapter, granular cell tumors have malignant potential. In a series of 183 patients with granular cell tumors, 4% were malignant. All of the malignant lesions found were larger than 4 cm.¹⁵ Despite their malignant potential, recurrence after endoscopic resection has not been described. These lesions are generally treated with endoscopic resection with biopsy forceps or endoscopic mucosal resection for lesions larger than 1 cm.

Lymphangiomas

Lymphangiomas are the result of congenitally malformed lymphatic tissue. Lymphangiomas are found most commonly in the skin, and they are extremely rare benign lesions in the esophagus. Fewer than 15 cases of esophageal lymphangiomas have been reported, all found in children younger than the age of 2 years. They appear as a translucent, yellow mass on endoscopy, and are generally managed conservatively, as most lesions are less than 5 mm. If they grow to a size of 4 to 5 cm and the patient becomes symptomatic, treatment such as band-assisted mucosectomy may be appropriate.¹⁶

Hemangiomas

Hemangiomas are also extremely rare diseases in the esophagus and are typically found incidentally. On endoscopy, they appear as nodular, soft, blanching bluish-red lesions that can be mistaken for Kaposi sarcoma. If symptoms exist, they usually consist of bleeding or dysphagia. Surgical or endoscopic resection has been used to treat symptomatic patients.¹⁷

Leiomyoma

Leiomyomas are the most common benign neoplasms found in the esophagus. They are smooth muscle lesions that arise from the muscularis propria and on occasion from the muscularis mucosa. They appear as spindle-shaped muscle fibers in a cascade or whirl-like pattern surrounded by a fibrous capsule on histology. One should suspect malignancy if increased cellularity, atypia, or mitotic figures are identified histologically.

Leiomyomas very seldom cause symptoms, but dysphagia, chest pain, bleeding (if ulcerated), reflux (if distal), and obstruction (if larger than 5 cm) all have been described. On esophogram, these lesions appear as rounded filling defects; on endoscopy, they appear as firm nodules with normal overlying mucosa (Fig. 28-7). Because the mucosa is normal, forceps biopsy is rarely helpful (unless the lesion happens to arise from the muscularis mucosa). On endoscopic ultrasound, they are hypoechoic and arise from the muscular layer of the esophagus, whereas computed tomography is not always useful in determining the layer of origin (Fig. 28-8A,B). These lesions are slow growing, and if encountered incidentally, smaller asymptomatic lesions can be treated conservatively. As with most muscle-derived tumors, such as sarcomas and gastrointestinal stromal tumors, lesions larger than 4 cm have an increased risk of malignancy and should be treated with resection.⁶ Unlike other parts of the gastrointestinal tract, however, leiomyomas are far more common in the esophagus than their malignant counterparts. Given the difficulty of clear diagnosis with endoscopic biopsy or fine-needle aspiration, resection is recommended to confirm the diagnosis of benign disease. Lesions that are greater than 2 cm or that are symptomatic should be surgically resected.

An inlet patch is an area of heterotopic gastric mucosa found just distal to the UES in up to 10% of thorough endoscopies (Fig. 28-9A). They are generally thought to be congenital in origin and result from incomplete replacement of columnar gastric epithelium with esophageal squamous epithelium.¹⁸ The patches appear as red velvety patches from 0.5 to 2 cm in diameter and can be composed of either antral- or fundic-type gastric mucosa. Fundic mucosa contains chief and parietal cells that have the capability of producing acid (Fig. 28-9B). Inlet patches are usually asymptomatic, but there has been a suggested association with globus sensation, which resolves with ablation.¹⁹ There have also been reports of association with helicobacter pylori infection and esophageal webs, rings, or strictures.²⁰ Only 24 reports of associated gastric adenocarcinoma have been published.¹⁸

Inclusion Cysts

Esophageal cysts are the second most common benign esophageal tumor. Inclusion cysts are intramural and typically occur near the tracheal bifurcation. They are filled with a brownish mucoid fluid and are lined with either ciliated columnar or stratified squamous epithelium. ¹¹

Duplication Cysts

It is important to distinguish esophageal tubular duplications from duplication cysts. True intestinal duplications are rare parallel channels that communicate with the alimentary tract; whereas duplication cysts do not communicate with the alimentary tract. The esophagus is the most common location for foregut duplication. Congenital tubular (or enteral) duplications are discussed in Chapter 51 (Fig. 28-10).

Esophageal duplication cysts are fluid-filled structures that typically occur in the posterior mediastinum, have a mucosal epithelial lining, and are located within the muscular wall of the esophagus.¹ Duplication cysts can produce a variety of respiratory and gastrointestinal symptoms as a result of extrinsic compression. Respiratory symptoms include cough, wheezing, dyspnea, aspiration, and pneumonia; and gastrointestinal symptoms include regurgitation, dysphagia, regurgitation, epigastric pain, and anorexia.²¹ More rarely, they are associated with hemorrhage, perforation, chest pain, cardiac arrhythmias, spinal cord symptoms, and malignancy.¹

Duplication cysts may be seen on esophogram as a compression on the esophageal lumen, or on endoscopy, as a submucosal mass (Fig. 28-11). These lesions are visible on CT or MRI and manifest as anechoic lesions on endoscopic ultrasound. An endoscopic fine-needle aspiration of the cyst fluid can help to find neoplastic cells in masses that are found incidentally, although only surgical excision truly rules out neoplasm.²¹ Surgical excision is the favored treatment because it has low morbidity.²² Occasionally, emergency endoscopic needle decompression is needed to treat life-threatening airway complications of duplication cysts.

An esophageal diverticulum is an outpouching of the esophageal wall. These abnormalities can include the entire wall (a true diverticulum) or just a part of the wall (a pseudodiverticulum involving protrusion of either the mucosa or possibly submucosa through the muscularis propria). They also may be categorized as pulsion versus traction. Pulsion diverticula occur as a result of propulsive forces from a bolus of food that causes herniation of part of the esophageal wall through a weakness in the muscular fibers. A traction diverticulum is a rare true diverticulum that results most commonly from chronically inflamed mediastinal lymph nodes that attach to and pull on the esophagus, eventually causing a protrusion of the entire esophageal wall.⁶

Esophageal diverticula also may be classified by their location. Proximal, more specifically pharyngoesophageal (Zenker's), diverticula are the most common. These are pseudodiverticula that occur above the UES and usually are acquired. There is an area of weakness in the decussation of the inferior pharyngeal constrictors called Killian triangle, where the circular muscular layer of the esophagus does not exist. Mucosa and submucosa typically protrude through this defect just above the cricopharyngeus.³ They occur more commonly in women and approximately 50% occur in patients in their seventh or eighth decade. They are thought to account for less than 5% of reported cases of dysphagia⁶ (Fig. 28-12).

Zenker diverticula are usually asymptomatic and are found incidentally on esophagoscopy or endoscopy as a posterior hypopharyngeal protrusion. A barium swallow is diagnostic. If symptoms do occur, patients report a vague sticking or globus sensation. Larger diverticuli can cause gurgling or even regurgitation. Some patients have reportedly learned maneuvers to empty the pouch.⁶ Asymptomatic patients do not need treatment. If troubling symptoms exist, however, several options for excision exist: endoscopic diverticulostomy, diverticulopexy, or diverticulectomy. A cricopharyngeal myotomy is included as part of the procedure to eliminate the distal functional obstruction that contributed to the formation of the pseudodiverticulum. For details regarding resection of diverticula, see Chapter 30.

Midesophageal diverticula can be traction or pulsion diverticula. Patients with chronic inflammatory thoracic disease such as tuberculosis or fungal infections can have inflammatory lymph nodes that scar and pull on the esophagus to cause traction diverticula. Motor dysfunction causing abnormal forces on the esophageal wall in patients with achalasia, LES dysfunction, spasm, or nonspecific motility disorders have been reported to cause pulsion midesophagus diverticula in some patients.²³

Distal or epiphrenic diverticula are the second most common type of diverticulum in Western society and can occur at all ages. These diverticula are usually the result of motor dysfunction, such as discoordination between the distal esophagus and the LES, achalasia, or diffuse esophageal spasm. Patients are usually asymptomatic, but the severity of the symptoms depends on the motor abnormality, the size of the diverticulum, and the size of the mouth of the diverticulum. A small diverticular mouth may limit spontaneous emptying of the diverticulum and contribute to symptoms of regurgitation. Symptoms described include chest pain and, less commonly, regurgitation. These lesions are typically diagnosed on barium swallow⁶ (Fig. 28-13). Symptomatic lesions are treated with either laparoscopic or thoracoscopic diverticulectomy and possibly fundoplication. Consideration also should be given to concurrent esophageal myotomy distal to the diverticulum. For details of the surgical approach to epiphrenic diverticula, see Chapter 30.

Esophageal webs are membranous diaphragms composed of stratified squamous epithelium, typically located in the cervical or midesophageal region. They usually are acquired and rarely are congenital. They may occur in an otherwise normal esophagus or may be associated with congenital anomalies such as tracheoesophageal fistula. Webs are found in 5% to 15% of patients undergoing radiologic or endoscopic evaluation for dysphagia.²⁴ Esophageal webs are similar to webs found in the small intestine and typically are composed of mucosa only.

Plummer—Vinson syndrome is described as an association between iron deficiency anemia and esophageal webs, although one report showed no correlation between the two.²⁵ Acquired esophageal webs can be the result of chronic ingestion of substances such as quinidine, aspirin, phenytoin, tetracycline, potassium chloride, and vitamin C¹. Esophageal webs are seen on esophogram as a shelf, best seen on a lateral view (Fig. 28-14). Most are asymptomatic, but they can cause dysphagia to solids. Webs are delicate tissue that can be treated easily with either passage of the endoscope at the initial diagnostic endoscopy or with more formal dilation.²⁶

Congenital webs are extremely rare, with only 30 reported cases. Congenital webs occur by incomplete coalescence of the vacuoles in the epithelial cells that fill the esophagus at approximately week 10 of gestation. If the diaphragm completely occludes the lumen, the treatment is surgical excision of the membrane shortly after birth.¹ More commonly, however, these diaphragms are incomplete and behave clinically as any other type of esophageal stenosis. Unlike esophageal rings (see below), they rarely encircle the entire esophagus, and typically project from the anterior or lateral esophagus.

There are two types of esophageal rings: mucosal rings (also termed “Schatzki ring”) and the rarer muscular ring. These rings partially occlude the lumen and can cause dysphagia. Muscular rings occur congenitally and are formed by a band of hypertrophied muscle covered by squamous epithelium approximately 2 cm proximal to the squamocolumnar junction. If symptomatic, these lesions can be treated either with dilation or with botulinum toxin.^27,28

Schatzki first described the “Schatzki ring” in 1944. It is a shelf-like membranous esophageal diaphragm of squamous mucosa located at the junction of the esophageal vestibule and the gastric cardia. These rings generally are asymptomatic but have been reported to cause dysphagia, most commonly in middle-aged men, when they narrow the lumen (<13 mm) enough that a food bolus cannot pass.²⁹ They are fairly common, with an incidence between 6% and 14% on esophogram.³⁰ They appear as a radiographic shelf in the mid-to-distal esophagus on esophogram¹ (Fig. 28-15). It is important to dilate the distal esophagus sufficiently to be able to see the ring on endoscopy. Most rings can be treated successfully with large bougie or balloon dilation with a recurrence rate of 13% in one series.³¹ Disruption of the ring with electrocautery has also been shown to be effective.²⁶

The benign esophageal diseases discussed in this chapter are limited to benign neoplasms and several structural abnormalities. Management of these lesions is discussed in the Chapters 29 and 30. For details regarding congenital esophageal disease, consult Chapters 50 and 51. See Chapters 32 to 35 for a detailed discussion of motility disorders. For more information regarding the pathophysiology and surgical treatment of esophageal malignancy, see Chapters 10 through 25.

The anatomy and histological anatomy of the esophagus are critical to the understanding of esophageal disease, staging of esophageal cancer, and therapeutic interventions. For example, the depth of invasion of early esophageal cancer needs to be determined precisely before deciding whether mucosal resection or esophagectomy is best for the patient, and new depth measurements (mucosal: m1–3, submucosal: sm1–3) have been proposed.

For leiomyoma, it is clear that large tumors (>4 cm) and symptomatic tumors need to be removed, preferably by minimally invasive enucleation. The dilemma is how to treat intermediate, asymptomatic tumors (>2 and <4 cm). One option is to follow up the patient every 6 months, and ultimately annually, with EUS or MRI to monitor the progression or stability of the lesion. Another option is to perform EUS-guided biopsies to determine the status of the biomarker, tyrosine-protein kinase (Kit or cKIT), and then only aggressively treat tumors that are cKIT positive. The one limitation to this approach is that the biopsy can cause local inflammation and increase the risk of a postoperative esophageal leak. We currently favor minimally invasive enucleation, particularly in cKIT-negative lesions, as opposed to esophagectomy.