29: Resection of Benign Tumors of the Esophagus

Benign tumors of the esophagus are rare cases encountered by a variety of specialists including gastroenterologists, general surgeons, and thoracic surgeons. The clinical presentation of these lesions may vary from asymptomatic, incidentally discovered tumors (most common) to large lesions resulting in important dysphagia or airway compromise. The development of minimally invasive approaches to esophageal pathology over the last decade has expanded the diagnostic and treatment options for these lesions.

Benign tumors represent less than 1% of all esophageal tumors, and less than 10% of all surgically resected esophageal lesions.^1,2 They may be classified based on either histology or location within the esophageal wall (mucosal, submucosal, or extraluminal) (Tables 29-1 and 29-2). The most common lesions include leiomyomas, esophageal cysts, fibrovascular polyps, and granular cell tumors. The development of endoscopic ultrasound (EUS) has improved the preoperative ­diagnosis of these lesions and is a helpful adjunct for clinical decision-making. Many of these lesions have a characteristic radiological appearance that eliminates the need for biopsy in many cases. Fine-needle aspiration (FNA) is often not required for diagnosis and may not be diagnostic in all lesions (e.g., in differentiating leiomyoma from leiomyosarcoma). Forceps biopsy is appropriate for mucosal lesions, but usually is unhelpful for submucosal or deeper lesions.

Benign tumors are generally asymptomatic and are discovered incidentally on imaging studies. Dysphagia is the most common presenting symptom and is more common with intraluminal tumors. Other presenting symptoms vary depending on the lesion, as described below, but may include vomiting, weight loss, gastrointestinal (GI) bleeding, substernal discomfort, cough, or regurgitation of pedunculated cervical lesions. Examples of intraluminal tumors include squamous cell papillomas, fibrovascular polyps, inflammatory pseudopolyps, and fibroneuroid tumors. Fibrovascular polyps are the most common, arise from the cervical esophagus, and generally are seen in men in the sixth or seventh decade of life. Squamous cell papillomas are small, sessile lesions found in the distal esophagus, most commonly seen in elderly patients.

Submucosal and intramural lesions are more commonly asymptomatic until they have grown to >5 cm in transverse diameter. Large tumors can cause obstructive symptoms such as dysphagia and emesis. Examples of these tumors include leiomyomas, granular cell tumors, lipomas, hamartomas, and neurofibromas. These tumors are difficult to differentiate on endoscopy, and EUS is helpful for making a diagnosis. Mucosal biopsy is not helpful for these lesions, and should be avoided in such cases because mucosal disruption may compromise subsequent enucleation of the lesions. FNA may be used in situations in which a diagnosis cannot be made by EUS alone, and does not threaten mucosal integrity.

All patients undergoing resection for a benign tumor should undergo a standard preoperative work-up and risk stratification as described in Chapter 4. The majority of benign tumors are asymptomatic, and other potential esophageal pathology should be evaluated carefully with a history, physical examination, and diagnostic studies to avoid an inappropriate operation. Evaluating for other esophageal pathology such as gastroesophageal acid reflux disease (GERD), achalasia, hiatal hernia, or a diverticulum also may help with assessing the need for additional procedures during resection of a benign tumor.

Diagnostic imaging for individual lesions is discussed in detail below, but often will involve a combination of barium swallow, endoscopy, and endoscopic ultrasound. Barium studies may help identify small lesions, especially those that are covered with normal mucosa and may easily be missed on endoscopy. Barium studies also will reveal other pathology including hiatal hernia, reflux, and diverticula that may need to be addressed at the time of surgery and may prompt additional preoperative testing. Endoscopy provides valuable information regarding the location of the tumor, whether there are multiple lesions, the continuity of the mucosa overlying the lesion, and other potential pathology. Endoscopic ultrasonography is invaluable in characterizing the size, layer of origin, and internal characteristics of lesions. EUS-directed FNA is frequently feasible as an aid to diagnosis. Intraoperative endoscopy also may be of assistance as described below.

Fibrovascular Polyp

Clinical Presentation and Diagnosis

Fibrovascular polyps commonly cause obstructive symptoms such as dysphagia, regurgitation, vomiting, and weight loss. These tumors originate near the thoracic inlet, adjacent to the cricopharyngeus muscle at C6, and grow on a pedunculated stalk. Symptoms may range from episodic regurgitation of the mass to laryngeal impaction and asphyxiation.^3,4 Large tumors are prone to ulceration at the tip and may be a source of GI bleeding.

On barium esophagram, these characteristically appear as smooth, lobulated, elongated filling defects starting at the level of the cervical esophagus (Fig. 29-1A,B). Computed tomography (CT) or magnetic resonance imaging (MRI) will show a dilated esophagus with a homogeneous, intraluminal soft tissue mass without invasion of surrounding structures. These studies can also identify the level of origin of the stalk. Endoscopy may be useful for identifying the site of origin and size of the lesion (Fig. 29-1C). However, small lesions may be missed because they are typically lined with normal-appearing mucosa. EUS is useful for identifying feeding vessels and predicting risk of significant bleeding during excision.

Management

Fibrovascular polyps are benign and may be treated with endoscopic excision; those with thin pedicles may be endoscopically ligated or cauterized.³ Factors that preclude safe endoscopic removal include vascular stalks that need to be ligated or cauterized, or tumors too large to be delivered through the upper esophageal sphincter. These lesions may require cervical esophagotomy for excision.^4,5 Lesions with features concerning for malignancy or those too large to be removed through a cervical esophagotomy may require a formal esophagectomy (see Chapters 15–22). Resection is recommended for all large fibrovascular polyps because of the risk of regurgitation and asphyxiation.

For fibrovascular polyps that are treated surgically, the location of the tumor stalk or pedicle should be evaluated preoperatively as described above. It is helpful to have endoscopy available for intraoperative localization. Consideration likewise should be given to performing a gastrotomy if necessary to facilitate removal of large lesions that extend into the stomach. The patient should be positioned and draped appropriately with these considerations in mind. The esophagus is approached through a longitudinal neck incision anterior to the sternocleidomastoid muscle on the side opposite to the tumor. Fibrovascular polyps generally originate just inferior to the cricopharyngeus muscle. A longitudinal esophagotomy is made at the level of the stalk origin. The incision must be long enough to deliver the tumor through the incision while the stalk is intact. The incision can then be extended distally to expose the entire stalk, allowing for submucosal resection of the tumor with the stalk (Fig. 29-2). The base of the stalk is then ligated, taking care to control any vessels supplying the tumor through the stalk. Complete excision of the pedicle is necessary to prevent recurrence. The esophagus is closed in two layers. Drains are not routinely placed.

Postoperative Care and Complications

Reported complications from this procedure are rare. A nasogastric tube is not routinely used. The patient can typically begin taking clear liquids on the first postoperative day. No routine postoperative imaging is required. Recurrence of fibrovascular polyps is rare but has been reported and appears to occur more commonly after endoscopic polyp resection.⁶

Squamous Cell Papillomas

Squamous cell papillomas are rare tumors typically found in the lower third of the esophagus. They are thought to be etiologically linked to human papillomavirus (HPV) and GERD. They are small in diameter (usually <1.5 cm), pink or white in color, soft, and have a smooth or slightly rough surface. They may appear similar to superficial squamous cell carcinomas, but can easily be differentiated histologically. There is no evidence that they progress to malignancy, and thus do not need to be removed unless they are symptomatic.^2,7 Their small size and superficial location make these lesions good candidates for endoscopic resection. The recurrence rate is low for lesions that have been completely excised.

Leiomyoma

Clinical Presentation and Diagnosis

Leiomyomas are the most common benign tumors of the esophagus, accounting for more than half of all benign tumors in some reports.^8,9 They typically present between the ages of 20 and 69 years, and the peak incidence is between the third and fifth decades. As with other benign tumors, they often are asymptomatic. Patients with symptoms may describe dysphagia, weight loss, chest pain, or early satiety. The lesions grow slowly, arise from smooth muscle cells, and are predominantly found in the lower two-thirds of the esophagus. Leiomyomas rarely ulcerate or bleed. There is some controversy regarding the malignant potential of these lesions.⁹

Leiomyomas have a typical appearance on barium swallow as rounded, smoothly marginated intraluminal filling defects. Large tumors show an acute angle with the wall of the esophagus and the tumor edge. A contrast swallow is useful for identifying the level and laterality of the lesion for surgical planning. Endoscopy may be useful in identifying the location of the tumor. Endoscopic characteristics of leiomyomas include normal-appearing overlying mucosa, mobile lesions, and projection into the lumen (Fig. 29-3A). Endoscopic forceps biopsy is contraindicated in patients with leiomyomas since it has not been shown to assist in obtaining a definitive diagnosis and puts patients at increased risk for complications such as bleeding, infection, and perforation at the time of enucleation. On EUS, these lesions are smooth, well-circumscribed, hypoechoic tumors originating from the fourth layer with an intact and uninvolved overlying mucosa¹⁰ (Fig. 29-3B). EUS provides the opportunity for FNA, which has been used in some case reports to differentiate between leiomyomas and leiomyosarcomas, although studies investigating the safety and efficacy of this technique are still pending.

Surgical excision is indicated in patients with symptomatic lesions. In asymptomatic patients, resection historically has been the treatment of choice and is recommended for tumors with increasing size, mucosal ulceration, or when tissue is needed to confirm the diagnosis. Resection is often ­recommended for lesions >4 cm in asymptomatic patients regardless of whether other abnormalities indicating increased risk are present. Observation of small, characteristic, asymptomatic lesions with serial EUS every 1 to 2 years has been recommended by some authors.¹¹

Endoscopic Resection for Leiomyoma

Endoscopic treatment can be considered for a limited group of lesions originating from the muscularis mucosa with intraluminal growth or polypoid growth patterns.¹² Tumors smaller than 2 cm that are pedunculated may be resected via endoscopic lumpectomy, while larger lesions may be treated with ethanol injection followed by lumpectomy. Lumpectomy is performed with a snare wire and suction cylinder after dissecting the tumor free from the submucosa using hypertonic saline injection. For larger lesions, multiple ethanol injections are administered over several weeks. Use of both of these techniques is more prevalent in Japan and is not yet common in Western countries. Reports have shown complete resolution of symptoms, negligible mortality, and low rates of recurrence.¹²

Surgical Enucleation for Leiomyoma

The location of the tumor should be evaluated preoperatively with endoscopy to facilitate surgical planning. Endoscopy should be available in the operating room for localization, transillumination, and leak identification during resection. The patient is positioned to facilitate either a right or left approach according to the level of the lesion (see below). Double-lumen endotracheal intubation is used to improve intraoperative exposure if a transthoracic approach is selected. Laparoscopy or an upper midline laparotomy may be used for distal esophageal lesions.

Tumors in the lower esophagus may require mobilization of the cardia and disruption of the hiatal structures. Performance of a simultaneous antireflux procedure should be discussed with these patients before surgery. Patients with preoperative symptoms of reflux should undergo preoperative evaluation including pH monitoring and manometry (see Chapter 37). Concomitant antireflux procedures are also recommended in these patients.

Transthoracic enucleation has been the procedure of choice for removal of most leiomyomas.^11,13 Open thoracotomy or video assisted thoracic surgery (VATS) may be used according to surgeon preference. Tumors in the upper two-thirds of the esophagus are usually accessed from the right side, while lower third lesions are removed from either the left or the right side. After the esophagus is exposed, the lesion is identified using palpation and/or transillumination with endoscopy. The esophagus is mobilized sufficiently to identify the circumferential extent of the tumor. The azygos vein may be divided as necessary to gain adequate exposure. A longitudinal myotomy is then made overlying the tumor; this incision can be smaller than the length of the tumor. The leiomyoma will appear as a smooth, avascular, gray-white mass. Blunt dissection, hook cautery, and scissors are used to mobilize the tumor from the muscle layer and underlying submucosa. A traction suture may be placed in the tumor to assist in freeing it from the underlying tissue. Endoscopic visualization can be used during dissection to identify any mucosal damage.

After the tumor is removed, the endoscope is used for insufflation, possibly using distal occlusion of the esophagus. The esophagus is submerged in saline to observe for any air leak, which is an indication of a mucosal leak. Preoperative endoscopic biopsy predisposes to scar tissue formation that makes the tumor more adherent to the mucosa and increases the risk of intraoperative mucosal damage. Mucosal damage identified during surgery is repaired in two layers with absorbable sutures. In this case, delay of oral feedings for several days should be considered. After mucosal integrity is confirmed, the muscular layer is approximated without tension. Some authors suggest not closing the muscular layer if there is evidence of significant trauma after resection. A flap of pleura, pericardium, diaphragm, omentum, or pedicled intercostal muscle may be used as a buttress for the closure, but this is rarely necessary if the muscle layer is preserved in good condition and the closure of the muscle layer is secure. Failure to close the muscle layer or otherwise reinforce the area of myotomy may predispose to the development of a pseudodiverticulum (Fig. 29-4).

Postoperative Care and Complications

Nasogastric tubes are used according to surgeon preference, but likely provide little benefit. Patients without mucosal ­damage or evidence for a leak may be started on a clear liquid diet on the day of surgery, while feeding should be deferred for at least 1 day in patients who require mucosal repair. The diet is advanced to pureed and then mechanical soft foods over 7 to 10 days. Routine postoperative imaging of the esophagus is not required.

Enucleation of leiomyomas gives excellent results, with 89% to 95% of patients free of symptoms at 5 years.^11,13 Mortality rates range from 0% to 1.3%. Postoperative complications include acid reflux, esophagitis, fistula, stenosis, and diverticulum formation. Some of these may result from impairment in esophageal propulsion and inability to clear acid after resection of large tumors when the muscle layer is not adequately reapproximated.

Segmental Resection

Segmental esophageal resection should be considered for large tumors (>8 cm), circumferential tumors, those with significant distortion of the musculature, or those with high suspicion for leiomyosarcoma based on imaging or FNA. It should also be considered in patients undergoing enucleation when there is extensive damage to the esophageal mucosa predisposing the patient to a high risk of postoperative leak. Preoperative planning in all of these patients should include consideration of conduit reconstruction. Reconstructive options include gastric pull-up or colonic or jejunal interposition. Preoperative preparation and positioning are similar to those for enucleation procedures. Techniques and postoperative care for segmental esophageal resection are discussed in Chapters 15-22.

Lipomas and granular cell tumors have typical appearances on EUS and can be diagnosed without biopsy. Granular cell tumors are yellow, firm nodules located in the distal esophagus that arise from the first or second layer as seen on EUS. They have a 1% to 3% malignancy rate, and resection should be considered for lesions >1 cm in diameter or those that are symptomatic. Endoscopic mucosal resection (EMR) has been described for these lesions with good outcomes.¹² Those that are not resected should be followed with endoscopy and EUS to rule out malignancy.

Lipomas are soft, yellow lesions covered with normal mucosa. They appear as homogeneous, hyperechoic lesions confined to the submucosal layer on EUS. They do not progress to malignant lesions, and resection is generally indicated only for symptomatic lesions. Asymptomatic lipomas do not require any specific follow-up.

Hemangiomas are typically located in the middle and lower esophagus. They may present with bleeding or dysphagia and sometimes are mistaken for varices. On EUS, they are hypoechoic, have sharp borders, and arise from the second or third layer. Biopsy is not recommended as this has been associated with significant hemorrhage. Treatment options include sclerotherapy, fulgurization, radiotherapy, EMR, tumor enucleation, and formal esophagectomy, depending on the size of the lesion and the patient's clinical presentation.¹² Reports of treatment with EMR and other endoscopic techniques are largely anecdotal, with successful immediate outcomes but limited long-term follow-up.¹⁴

Esophageal Cysts

Esophageal cysts are the second most common benign esophageal tumor. They are typically extramural, with epithelial and muscular components that are continuous with the muscularis propria. They are commonly located near the tracheal bifurcation. They are evident as cystic lesions on CT and endoscopic ultrasound, but sometimes may appear dense because of thickened contents or previous hemorrhage. Cysts can lead to a host of complications including ulceration, hemorrhage, perforation, airway obstruction, dysphagia, and repeated pulmonary infections.² Resection is recommended for all esophageal cysts. They are discussed in more detail in Chapter 28.

A 59-year-old male presented to surgery clinic after an annual whole-body CT scan revealed an intramural mass just proximal to the gastroesophageal (GE) junction (Fig. 29-5A). He denied any symptoms from the lesion, including dysphagia, pain, weight loss, or reflux. He had no other significant past medical or surgical history. His physical examination was unremarkable. His preoperative laboratory results revealed a normal hematocrit (45.5%). An upper endoscopy and EUS were performed and revealed a tortuous, intramural, noncircumferential lesion extending from the distal thoracic esophagus to the GE junction (38–42 cm from the incisors) (Fig. 29-5B). It originated from the fourth layer on EUS, and had well-circumscribed borders (Fig. 29-5C). It was 6 cm in diameter (Fig. 29-5D). The remainder of the esophagus was normal. An FNA was performed, and cytology confirmed the diagnosis of leiomyoma; immunohistochemistry was negative for S100, CD117, and DOG1. Resection was performed via a laparoscopic approach. The distal 10 cm of the esophagus was exposed, and the mass was readily apparent anteriorly. The esophagus was mobilized circumferentially in the mediastinum to bring the cephalad aspect of the mass to the level of the hiatus. Intraoperative endoscopy was used to confirm the proximal and distal margins of the mass. The muscular layers on the anterior surface of the esophagus were incised to expose the mass, and a combination of blunt dissection, hook monopolar cautery, and LigaSure™ (Covidien, Mansfield, MA) were used to mobilize the mass from the submucosa. The mass was removed and endoscopic insufflation was used to confirm that the submucosa remained intact. The posterior crural pillars were reapproximated and a partial anterior (Dor) fundoplication was performed. No drains were left. The patient was given clear liquids by mouth on the first postoperative day, and then was advanced to a soft mechanical diet the next day. He was discharged home on day 3, and was seen 2 weeks postoperatively, at which time he was tolerating a regular diet without symptoms of reflux or dysphagia. The final pathology revealed a 6.5-cm leiomyoma.

Benign esophageal tumors are rare, frequently are asymptomatic, and usually are discovered incidentally on CT, barium esophagram, or endoscopy. They are classified according to histology or esophageal layer of origin. Accurate diagnosis of these tumors is usually possible through imaging using barium esophagram, endoscopy, EUS, and CT scan. Biopsy is generally not required to establish a diagnosis, and is usually contraindicated for intramural tumors that may require enucleation. Many of these tumors require no treatment or may be safely resected using endoscopic techniques. Surgery is reserved for fibrovascular polyps, very large tumors of other histologic types, and those for which imaging is not able to rule out malignancy. Outcomes for surgical resection of these lesions are excellent and will continue to improve with the increased use of minimally invasive approaches.

Benign esophageal lesions generally can be resected by means of minimally invasive surgery and/or endoscopic surgery. Preoperative evaluation, diagnosis, and staging are paramount to exclude cancer and define the surgical objectives. The distal esophagus and GE junction can be easily accessed via a laparoscopic approach, which permits enucleation of even large and circumferential leiomyomas provided that adequate pre- and frozen-section evaluation excludes the presence of an aggressive tumor. Such extensive resection often requires complete mobilization of the GE junction followed by a complete or at least partial fundoplication, both to protect the mucosa and to reestablish the lower esophageal sphincter.