bubble_chart Overview

Benign esophageal tumors are rare, accounting for approximately 0.5% to 0.8% of all esophageal tumors. Due to mild or absent symptoms, patients often do not seek medical attention, or the condition is overlooked by clinicians. In recent years, with advancements in X-ray and other diagnostic techniques, the number of detected cases has gradually increased, with esophageal leiomyomas making up about 90% of these cases.

bubble_chart Pathological Changes

Esophageal leiomyoma originates from the intrinsic muscle layer of the esophagus, primarily the longitudinal muscle. The majority are located within the esophageal wall, i.e., the outer wall of the mucous membrane. Occasionally, they protrude into the lumen in a polypoid shape, connected to the esophageal wall by a stalk. There have been reports of such tumors being vomited out of the mouth, and these patients may also experience airway obstruction leading to suffocation during vomiting. The tumor can occur in any part of the esophagus. Domestic reports indicate that it is most common in the middle segment, followed by the lower segment, and least common in the upper segment. It is extremely rare in the cervical segment because the cervical esophagus is composed of voluntary muscle. It is also uncommon in the abdominal segment, making it difficult to distinguish whether it originates from the esophageal or cardiac muscle layer. The vast majority of tumors are solitary, with multiple tumors accounting for only about 2–3%, ranging from 2 to more than 10. The literature also mentions diffuse esophageal muscle tumor diseases. The size of the tumors varies, with 2–5 cm being the most common. Resected specimens have ranged from as small as 0.5 cm × 0.4 cm × 0.4 cm to as large as 17 cm × 10 cm × 6 cm. By weight, the smallest is 0.25 g, and the heaviest is 5,000 g.

The tumors are round or oval, but some are irregular in shape, such as lobulated, spiral, fresh ginger rhizome-shaped, or horseshoe-shaped as they grow around the esophagus. Esophageal smooth muscle tumor diseases with multiple tumors can cause thickening of the entire esophageal wall, posing certain diagnostic challenges. The tumors are firm and tough, often with a complete membrane, and the surface is smooth. They mainly grow outward and develop slowly. The cut surface appears white or yellowish. Histological sections show well-differentiated smooth muscle cells, elongated and spindle-shaped with clear boundaries. The tumor cells are arranged in bundles or whorls, mixed with a certain amount of fibrous tissue, and occasionally nerve tissue can also be seen. Esophageal leiomyomas rarely transform into fleshy tumors. Some literature reports a rate of 10.8%, but other scholars believe that fleshy tumors are a separate disease, with no direct evidence indicating malignant transformation from smooth bone tumors.

bubble_chart Clinical Manifestations

About half of patients with leiomyomas are completely asymptomatic and are discovered incidentally during chest X-rays or gastrointestinal contrast studies for other conditions. Even when symptoms are present, they are often mild, with the most common being grade I dysphagia, which rarely affects normal eating. The disease course can last from several months to over a decade. Even when the tumor is quite large, due to its slow progression, obstructive symptoms are usually not severe—a key point in differential diagnosis, as it differs significantly from the rapidly progressive dysphagia caused by esophageal cancer. Dysphagia may also be intermittent, and its severity does not always correlate with tumor size or location, depending mainly on the degree of tumor encirclement of the lumen, as well as mucosal edema, erosion on the tumor surface, and psychological factors. A small number of patients report pain, which can occur in various locations such as behind the sternum, the chest, back, or upper abdomen as a dull ache, with severe pain being rare. Pain may occur alone or alongside other symptoms. Around one-third of patients experience digestive disturbances, manifesting as heartburn, acid reflux, abdominal distension and fullness, postprandial discomfort, and indigestion. A few patients may exhibit symptoms of upper gastrointestinal bleeding, such as hematemesis and melena, likely due to mucosal erosion or ulceration on the tumor surface.

Associated conditions include esophageal cancer (though there is no direct relationship, as esophageal cancer is a common disease), hiatal hernia, diverticula, esophageal hemangioma, and achalasia.

bubble_chart Diagnosis

The diagnosis primarily relies on chest X-rays and esophagoscopy.

1. X-ray Examination Larger esophageal leiomyomas that grow toward the esophagus may protrude the mediastinal pleura into the lung field, appearing as a soft tissue shadow on a plain chest film. The reported detection rate ranges from 8% to 18% in the literature, and this condition should be considered in the differential diagnosis of mediastinal tumors. Some leiomyomas may show calcifications on plain films, with reports indicating a rate of up to 1.8%.

Barium swallow X-ray examination is the primary diagnostic method for this condition. Combined with clinical manifestations, a definitive diagnosis can often be made with a single contrast study. The findings depend on the tumor's size, shape, and growth pattern. The main feature is an intraluminal filling defect, which appears as a round or oval shadow with smooth, sharp edges and clear demarcation from the normal esophagus. The angles at the upper and lower ends of the filling defect, where it meets the normal esophagus, may be acute or grade I obtuse, depending on the degree of tumor protrusion into the lumen. In the frontal view, the tumor contour perpendicular to the long axis of the esophagus appears as a semicircular shadow due to the contrast of the barium, forming a "ring sign." The mucosal membrane is displaced, and the folds disappear, with a thinner layer of barium in the area, creating a "waterfall sign" or "smear sign." Larger tumors may show a soft tissue shadow at the site of the filling defect. Fluoroscopy reveals that the barium pauses slightly above the tumor before flowing through the space between the tumor and the opposite esophageal wall in a ribbon-like manner, resembling a small groove. The esophageal wall near the tumor remains flexible with good contraction, and the proximal esophagus does not dilate. Multiple leiomyomas or horseshoe-shaped tumors encircling the esophagus may cause an uneven lumen and obscure mucosal folds, requiring differentiation from esophageal cancer. The latter exhibits rigid walls, irregular filling defects, mucosal destruction, and ulcerations. The difference between esophageal leiomyoma and mediastinal tumor compression lies in the latter's shallower filling defect at the esophageal wall, an obtuse angle between the tumor and the wall on tangential views, and bilateral esophageal wall displacement to one side. Barium swallow may also reveal other complications, such as esophageal diverticula or hiatal hernias.

2. Fiberoptic Esophagoscopy Most leiomyomas can be diagnosed via barium swallow, and the addition of fiberoptic esophagoscopy (commonly using a gastroscope) increases the diagnostic accuracy to over 90%. This allows assessment of the tumor's location, size, number, and shape. The examination reveals a protruding mass in the esophageal lumen with intact, smooth, and flat mucosa, absent folds, and a faint reddish translucency. The edges of the leiomyoma are vaguely visible, and slight grade I movement of the tumor may be observed during swallowing, with rare luminal narrowing. If the mucosa appears normal, biopsy should be avoided, as it may fail to obtain tumor tissue, injure the normal mucosa, and cause adhesions between the mucosa and tumor, complicating future submucosal tumor resection and potentially necessitating partial esophageal resection. If mucosal changes are present and malignancy cannot be ruled out, a biopsy should be performed.

3. CT and Magnetic Resonance Imaging (MRI) While most diagnoses are confirmed by barium swallow and esophagoscopy, a few cases, particularly mid-esophageal leiomyomas, may be confused with aortic arch tumors, vascular compression, or malformations. CT and MRI aid in differential diagnosis. CT can also assess the tumor's extraluminal extension and precise location, assisting in surgical planning and incision design. Ultrasound may also detect certain tumors.

bubble_chart Treatment Measures

Surgical Treatment: Although leiomyoma is a benign disease, it has the potential for malignant transformation. Generally, it grows slowly, but the lesion progresses continuously. When it becomes large, it can compress surrounding tissues and cause a series of complications. Therefore, except for cases where the patient is older, the tumor is small, there are no obvious symptoms, the cardiopulmonary function is too poor to tolerate surgery, or the patient refuses surgery (in which case follow-up observation may be considered), surgical treatment is recommended once the diagnosis is confirmed.

Incision Selection: The surgical approach is determined by the tumor location, so detailed preoperative X-ray localization is necessary. Pedunculated leiomyomas often have their base in the cervical esophagus, and a pharyngeal or oblique neck incision is used. For tumors in the upper esophagus, a right anterior or posterolateral incision is chosen. For those in the middle or lower esophagus, a left or right posterolateral thoracotomy incision is employed.

Surgical Method: Most cases can be treated with submucosal tumor enucleation. Before surgery, a gastric tube without side holes (the distal side-hole segment is cut off) is placed. After thoracotomy, based on the preoperative X-ray localization, the esophagus is mobilized near the tumor. Once the mass is palpated, the segment of the esophagus is gently pulled out of the mediastinum with a tape. At the most prominent part of the tumor, where the muscle layer is thinnest, the muscle fibers are bluntly separated longitudinally to expose the tumor. After identifying the interface, the tumor is carefully dissected along its outer membrane to avoid injuring the mucosa. After tumor removal, if mucosal injury is suspected, the gastric tube is pulled to the surgical site, and the esophagus above and below is temporarily occluded with tapes. Warm saline is injected into the thoracic cavity, and air is introduced through the gastric tube to check for fistula formation. If a defect is found, it is repaired with fine sutures, with knots tied inside the lumen. The muscle layer is loosely sutured. If the muscle layer is very thin, nearby mediastinal pleura, pericardium, or diaphragmatic patches can be used for reinforcement. If necessary, intercostal muscle flaps can be mobilized for coverage. For larger defects, a Dacron patch may be used to prevent postoperative diverticulum formation. Larger tumors may require mobilization of a longer segment of the esophagus, but esophageal necrosis is rare. Literature reports cases with over 10 cm of mobilization that recovered well.

A minority of patients (10% in large foreign case series, 13.2% in China's 522 cases) require partial esophagogastrectomy. Indications include: ① Large, irregular tumors with severe adhesion to the esophageal mucosa, making separation difficult. ② Multiple leiomyomas that cannot be individually removed. ③ Suspicion of malignancy that cannot be ruled out by frozen section during surgery (distinguishing leiomyoma from leiomyosarcoma by frozen section is challenging, especially for well-differentiated leiomyosarcoma). ④ Leiomyoma combined with esophageal cancer or a giant diverticulum. ⑤ Severe intraoperative adhesion between the tumor and mucosa, with extensive mucosal damage that is difficult to repair.

Surgical Outcomes: Submucosal tumor enucleation has few complications and excellent results, with almost no reports of postoperative recurrence, esophageal stricture, or swallowing dysfunction.