Leiomyoma is a benign tumor that is of smooth muscle in origin and usually arises from the muscularis propria or on occasion from muscularis mucosa [11]. It is the most common benign esophageal tumor, accounting for more than half of all benign tumors of the esophagus [27]. The tumors are mostly located in the lower two-thirds of the esophagus, and more than two-thirds of the tumors are found as an intramural-submucosal mass [5]. The peak age that the tumors are detected is between 30 and 50 years.

Most leiomyoma patients are asymptomatic, but when symptoms are present, they are mostly nonspecific and of long duration [12]. The most common presenting symptoms are dysphagia, retrosternal pain, and weight loss [27].

On the contrast-swallow study, leiomyoma may be seen as a rounded or lobulated, elevated filling defect with a sharp margin between the mass and the esophageal wall beneath the smooth mucosal surface. A CT scan of the chest is not specific for diagnosing leiomyoma, but it may be helpful for evaluation of large tumors that extend into the mediastinum to assess the interface between tumors and adjacent structures or tumors whose findings are atypical such as those exhibiting rapid growth, or ulcerated or inflamed mucosa. Endoscopy is indicated for evaluation of the mucosa. The lesion can appear on endoscopy as having normal overlying mucosa, moveable mass beneath the mucosa, and narrowing of the esophageal lumen without obstructing the passage of the scope. Cold forceps biopsy through the endoscope is contraindicated because it usually does not help in diagnosis, and risks complications such as bleeding, infection, and mucosal perforation at the time of enucleation. EUS is very helpful for diagnosis of leiomyoma, which is characterized as well circumscribed, homogeneous, and hypoechoic with a smooth outer border, usually arising from the fourth layer or muscularis propria [8]. Fine-needle aspiration (FNA) of the lesion can be done during performing EUS. Although, there are some reports mention about the effectiveness of EUS-FNA in helping to obtain more definite diagnosis of esophageal leiomyoma [28, 29], some authors proposed that it provided no significant benefit especially in differentiating benign leiomyoma from malignant leiomyosarcoma [8, 30]. Thus, the effectiveness of this technique is still uncertain.

Resection of the tumor is indicated in symptomatic cases. For asymptomatic patients, the indication for tumor removal includes tumor size ≥5 cm, an increase in tumor size, mucosal ulceration or suspicion of malignancy [12, 18].

Endoscopic resection: Leiomyomas can be removed by various endoscopic methods as described above but only in selected cases and by capable endoscopists. Small (<2 cm) pedunculated leiomyomas originating from the muscularis mucosa can be resected using snare polypectomy [12]. Rubber band ligation through the scope at the neck of a small mass has also been reported [19]. Wider-based lesions may be removed by EMR or enucleation. EMR is performed by using a snare wire after injection of normal saline or other appropriate solution to lift the submucosal layer from the muscularis propria in order to cause protrusion of the tumor into the lumen [18]. For larger lesions, multiple sessions of ethanol injection into the mass through the scope may be an option with complete sloughing of the lesion without serious complication [31, 32], but this method is not common in the USA and other western countries and should be done by a skilled endoscopist. Endoscopic submucosal dissection (ESD) was originally reported as a treatment option for early gastric cancer and other superficial gastrointestinal cancers in Japan and has also been reported as a treatment of esophageal leiomyoma originating from the muscularis propria [21]. However, with a concern of its efficacy and safety, more studies will be needed before being considered as a standard treatment.

Minimally invasive surgery: Thoracoscopic and laparoscopic approaches for both enucleation and esophageal resection are standard treatments for esophageal leiomyoma. For tumors smaller than 5 cm, enucleation via thoracoscopic or laparoscopic approach is recommended. In the cases of larger tumors, circumferential lesions, significant distortion of the esophageal musculature, high suspicion of malignancy, or extensive damage to the esophageal mucosa, segmental esophageal resection is suitable either via minimally invasive techniques or through a laparotomy or thoracotomy [11].

To perform enucleation, the selected side for the operation depends on the location of the tumor. Localizing the tumors is accomplished by visualization, palpation, or endoscopy. Enucleation is done by longitudinal incising and splitting the muscle fibers over the mass and then dissecting the mass from the attached muscle and submucosal tissue without disrupting the mucosa. The details of minimally invasive techniques will be discussed later in this chapter.

Granular cell tumor (GCT) is a rare submucosal tumor of the esophagus. It can be found in many different organs, most frequently in the tongue, skin, breast, and muscle and uncommonly at the gastrointestinal tract [33]. GCT has been assumed to originate from neural tissues since its ultrastructural and immunologic-staining appearances are similar to those of Schwann cell [33]. As an intramural tumor, the presenting symptoms of GCT are almost the same as for leiomyoma, and most of the patients are asymptomatic. The endoscopic findings of GCT may include a yellowish polypoid lesion beneath the thin mucosa. Endoscopic biopsy is frequently nondiagnostic, but a diagnosis may be accomplished with multiple biopsies taken from the same site [18]. GCT appears on EUS as a hyperechoic solid mass surrounded by a hypoechoic submucosa. There is a 1–3 % malignancy rate among all GCTs; there appears to be no potential for malignant transformation in instances in which the GCT histologically is benign [18].

Resection should be considered for lesions >1 cm in diameter or for those that are symptomatic.

Endoscopic mucosal resection is appropriate for lesions that do not extend beyond the submucosal layer [18, 20]. Other treatments have been described including ethanol injection [34] and minimally invasive surgical enucleation [14].

Hemangiomas of the esophagus are benign vascular tumors that arise from the submucosal layer. They can be found throughout the esophagus [1]. Most patients are asymptomatic. Among patients who do have symptoms, dysphagia and bleeding are the most common complaints. Bleeding from rupture of the hemangioma can be massive and fatal. At endoscopy the lesions appear as bluish, polypoid, or sessile submucosal masses. On EUS, they usually occupy the 2nd or 3rd layer and have a sharp border. CT and MRI help in diagnosis and treatment planning, especially for large tumors. Given the concern for massive hemorrhage, biopsy is not recommended.

Intervention for esophageal hemangiomas should be considered regardless of whether patients have symptoms because of the high risk of bleeding [18].

Many endoscopic methods have been proposed including sclerotherapy (similar to the treatment for varices), laser fulguration, and EMR [18, 35, 36]. Surgical treatment is another choice including enucleation and resection of the esophagus by minimally invasive or open techniques [37].

Lipomas of the esophagus are usually found incidentally. Most lipomas of the thoracic esophagus are intramural, whereas those located in the cervical esophagus are mostly pedunculated. They usually appear soft and yellowish and are located beneath intact mucosa. EUS demonstrates the lesions to be homogenous, hyperechoic, and with sharp margins confined to the submucosal layer [11].

Resection should be performed in symptomatic patients or for larger pedunculated lesions in the cervical esophagus.

Treatment options include endoscopic resection and ligation or stapling for pedunculated lesion. Otherwise, enucleation can be done by transcervical, transthoracic, VATS, or laparoscopic approaches. Transgastric laparoscopic resection via stapling of a long-stalked, pedunculated thoracic esophageal lipoma has been performed successfully, with tumor removal through the transgastric port [38].

Fibrovascular polyps are the most common benign intraluminal tumor. It is thought that the tumor is formed from an area of submucosal thickening, then gradually protrudes into esophageal lumen aided by esophageal peristalsis. Most of the lesions are located in the cervical esophagus, just distal to the cricopharyngeus muscle in the region of Laimer’s triangle. Clinical presentations include dysphagia, regurgitation, retrosternal pain, weight loss, and airway obstruction [11]. Large lesions with a long stalk that extend into the stomach may develop superficial ulceration which results in bleeding and anemia. Contrast esophagography usually shows a smooth, lobulated, elongated filling defect. The findings from CT and MRI can also demonstrate differing density or attenuation, depending on the relative amounts of fibrous and adipose tissue in the mass [39]. Endoscopy can identify the site of origin and size of the lesion. However, a small polyp may be missed since its origin is most often in the proximal esophagus and the lesion is typically covered with normal mucosa. EUS may be of use in large-stalk lesions to assess the feeding vessels that may put the patient at risk for bleeding after resection [18].

All large or elongated-stalk polyps should be removed because of the potential risks of respiratory complications including airway obstruction from regurgitation of the polyp and aspiration into the proximal airway.

Most small polyps or thin stalk lesions can be removed via endoscopic methods such as snare polypectomy or EMR. Large polyps in the cervical esophagus may require left cervical esophagotomy for tumor removal [40]. The main goal of treatment is to remove the polyp base completely to prevent local recurrence.