Esophageal smooth muscle tumor Wikipedia business card is a neoplastic disease that usually presents with a milder sensation of obstruction to swallowing or dull pain behind the sternum. The symptoms tend to come on intermittently. It may be accompanied by epigastric discomfort, acid reflux, belching and loss of appetite.
Pathology Esophageal smooth muscle tumors originate from the intrinsic muscle layer of the esophagus, mainly from the longitudinal muscle, and most of them are in the wall of the esophagus, i.e. the outer mucosal wall is in the type. The majority of them are in the wall of the esophagus, i.e. the outer mucosal wall. Some of them are polyps in the lumen of the tube, with a tip attached to the wall of the esophagus, and have been reported to be vomited out of the mouth. Tumors can occur in any part of the esophagus, but in China, the middle segment is the most common, the lower segment is the second most common, the upper segment is the least common, and the cervical segment is the least common, because the cervical segment of the esophagus is composed of random muscle, and the abdominal segment is not common, so it is not easy to distinguish between the esophagus and the cardia muscle layer. Most of the tumors are solitary, and only about 2% to 3% are multiple, ranging from 2 to more than 10. Tumors vary in size, with 2-5 cm being the most common. Excised specimens range from as small as 0.5 cm × 0.4 cm × 0.4 cm to as large as 17 cm × 10 cm × 6 cm, with the smallest being 0.25 g and the heaviest being 5000 g by weight.
The tumors are round and oval in shape, but there are also irregular shapes, such as lobulated, spiral, ginger-shaped, and horseshoe-shaped growing around the esophagus. In esophageal smooth muscle tumor disease, there are multiple tumors that can thicken the whole esophageal wall, so it is difficult to diagnose. The tumor is tough, with an intact envelope and smooth surface. The tumor grows mainly outside the lumen and is slow growing. The tumor cells are arranged in bundles or swirls, with a certain amount of fibrous tissue and occasionally nerve tissue. Esophageal smooth muscle tumor becomes sarcoma rarely, some literature reports 10.8%, but some scholars believe that sarcoma is another independent disease with no direct evidence of malignant change from smooth bone tumor.
Clinical symptoms About half of the patients with smooth bone sarcoma are completely asymptomatic and are detected by chest X-ray or gastrointestinal angiography for other diseases. Those that do have symptoms are mild, most commonly a mild dysphagia that rarely interferes with normal diet. Even if the tumor is quite large, the obstructive symptoms are not severe because of its slow development. This is important in the differential diagnosis, which is not quite the same as the short-term progressive dysphagia caused by esophageal cancer.
The severity of choking in esophageal smooth muscle tumor may also be intermittent, and its severity is not exactly parallel to the size and location of the tumor, but depends mainly on the growth of the tumor around the lumen, and is also related to the mucosal edema and erosion on the surface of the tumor and psychological factors. A small percentage of patients complain of pain, the location of which is variable and may be vague pain behind the sternum, chest, back and upper abdomen, but rarely severe. It can occur alone or in combination with other symptoms. About 1/3 of the patients have digestive disorders, such as heartburn, acid reflux, abdominal distension, postprandial discomfort and indigestion. Individual patients have upper gastrointestinal bleeding symptoms such as vomiting blood and black stool, which may be caused by mucosal erosion and ulceration on the surface of tumor.
The associated diseases include esophageal cancer (which is not directly related to each other because esophageal cancer is a common disease), esophageal hiatal hernia, diverticulum, esophageal hemangioma and pancreatic dyscrasia.
Examination and diagnosis
1.X-ray examination of large smooth muscle tumors growing into the esophagus and ejecting from the mediastinal pleura to the lung field, soft tissue shadows can be seen on the plain film of the cell, and its visibility rate is reported as 8% to 18% in the literature. Calcified foci can be seen on plain radiographs of individual smooth muscle tumors, with some reports reaching 1.8%.
Barium x-ray esophagogram is the main diagnostic method for this disease, and combined with clinical manifestations, the diagnosis can often be confirmed in a single imaging. What is seen on barium meal anon depends on the size and shape of the tumor and the growth pattern. Intraluminal filling defect is the main manifestation, which is round or oval with smooth and sharp edges and clearly demarcated from normal esophageal smooth muscle tumor. The junction angle between the upper and lower ends of the filling defect and the normal esophagus is acute or mildly obtuse depending on the amount of tumor protrusion into the lumen. The outline of the tumor perpendicular to the long axis of the esophagus in the orthostatic position is shown as a semicircular shadow due to the contrast of the barium meal, which appears as the “annular sign”. The mucosa at the tumor is ejected and the folds disappear, and the barium there is less than the surrounding area, forming a thin layer, forming the “waterfall sign” or “smear sign”. If the tumor is large, soft tissue shadow can be seen in the area where the filling defect is located. Under fluoroscopic observation, the barium passes through the tumor, stops slightly above the mass, and then passes through the tumor and the opposite esophageal wall in a band, like a small groove. The esophageal wall near the tumor is soft and well contracted, and the proximal esophagus is not dilated. Multiple smooth muscle tumors or horseshoe-shaped masses encircle the esophagus, making the lumen uneven and the mucosa poorly displayed, and the distinction with esophageal cancer should be noted. In the latter case, the canal wall is stiff and the filling defect is irregular, with mucosal destruction and niche shadow. The difference between esophageal smooth muscle tumor and mediastinal tumor is that the filling defect at the wall of the latter is shallower, and the barium shadow between the mass and the wall in the tangential position is at an obtuse angle, and the esophageal wall is bilaterally shifted to one side at the same time. Barium esophageal examination can also detect other concomitant diseases, such as esophageal diverticulum, hiatal hernia, etc.
2.Fiber esophagoscopy can diagnose most of smooth muscle tumors by barium meal, together with fiber esophagoscopy (in fact, fiber gastroscopy is often used), the accuracy of examination can reach more than 90%, which can understand the location, size, number and shape of tumors. On microscopic examination, we can see the mass protruding in the esophageal cavity, the surface mucosa is intact, smooth and spreading, the creases disappear, it is light red and translucent, the edge of myxoma is faintly visible, when swallowing activity, the mass can be seen to move up and down lightly, and there is not much lumen narrowing. If the mucosa is normal, the tissue should not be bitten for examination, because the tumor tissue cannot be taken and the normal esophageal mucosa is damaged, so that the mucosa and the tumor will adhere to each other and be easily broken when the extra-mucosal tumor is removed later, and even forced to perform partial esophagectomy and reconstruction. If there are changes on the mucosal surface, biopsy should be performed if malignant lesions cannot be excluded.
CT and magnetic resonance imaging (MRI) examination can help to diagnose most of the tumors after barium meal and fiberoptic esophagoscopy, but CT and MRI examination can help to differentiate the tumors in a few cases, especially in the middle smooth muscle tumors, which are sometimes mixed with aortic aneurysm, vascular compression or malformation. B-ultrasound can also detect certain tumors.
Differential diagnosis
1. Mediastinal tumors of larger size can cause soft tissue shadow in the mediastinum when they grow outside the wall, which can be easily mistaken for mediastinal tumors. Therefore, for the masses in the posterior lower mediastinum that are closely related to the esophagus, do not be satisfied with the diagnosis of mediastinal tumors, and be alert to the presence of esophageal smooth muscle tumors.
Esophageal smooth muscle tumor
2.Esophageal smooth muscle tumor involves longer esophagus, and the mucous membrane in the lesion area is thin and can be accompanied with congestion and other manifestations, so it is easy to mistake the destruction of mucous membrane and diagnose it as esophageal cancer during esophagogram.
The symptoms of mediastinal lymph node enlargement or inflammatory masses are dysphagia, barium meal examination shows filling defect in the middle part of esophagus, and esophagoscopy shows smooth spherical lesions in the middle part of esophagus, which are also similar in cases of mediastinal lymph node enlargement or inflammatory masses. In this case, if a lateral film or CT scan is taken at the same time as the barium esophagogram, the diagnosis of external pressure esophageal obstruction may be clarified.
4. Certain physiological variants such as external compression of the right vagus subclavian artery or saccular aneurysm, smooth indentation area produced by the left main bronchus and aortic arch, also need to be differentiated from the less common vertebral accessory compression. Although barium esophageal meal is the preferred method to diagnose esophageal smooth muscle aneurysm, CT is an excellent further examination tool if it is difficult to differentiate from external compression lesions, especially if the lesion is located at the level of the aortic arch and the level of the tracheal bulge.
Therefore, except for very small tumors with a diameter of 1 to 2 cm or less, without any symptoms, or patients who are old, weak, or with low cardiopulmonary function and other physical conditions not suitable for surgery, surgery is recommended once diagnosed. The surgical method and degree of difficulty can be determined according to the tumor site, size, shape, mucosal fixation, extent of gastric involvement and adhesion with surrounding tissues in a few cases. Surgery is mainly for extra-mucosal tumor removal.1. Although esophageal smooth muscle tumor is benign, it has the tendency of malignant transformation, and the long-term growth of tumor can compress the surrounding organs and bring a series of complications. The choice of surgical incision depends on the site of tumor. Upper middle esophageal tumor should be taken as right thoracotomy, while lower esophageal tumor and multiple lesions should be removed by left thoracotomy. However, care should be taken to avoid damaging the esophageal mucosa, especially when removing the mucosal fold at the bottom of the “sulcus” or “valley” formed by the nodule and the adjacent part of the nodule that is caught in the myxoma. If there is any mucosal damage, it can be detected by immersing the esophagus in water after gas injection through the gastric tube, and if there is any damage, it should be repaired properly. When the tumor is large and squeezes the adjacent mediastinal organs and pleural cavity, it is difficult to be removed, or when it encircles the whole esophagus (usually occurs at the junction of esophagus and cardia) and there is superficial ulcer, or when the lower segment of huge smooth muscle tumor extends downward beyond the cardia into the stomach, or when the mucosa is broken too much during the removal and cannot be repaired satisfactorily, or when it is combined with esophageal cancer, partial esophagectomy and esophagogastric anastomosis are feasible. Excision is safe, with a mortality rate of 1% to 2%, and no recurrence has been reported after surgery, while the mortality rate of resection is 2.6% to 10%.
(1) Surgical methods
This procedure is suitable for those with small tumor and no adhesion between tumor and mucosa, and it is the ideal procedure.
The tumor can also be removed by televised thoracoscopic excision of extramucosal tumor for a definite diagnosis of esophageal smooth muscle tumor. It is believed that benign smooth muscle tumor with the size of 5cm×5cm×5cm can be removed by TV thoracoscopy, supplemented by TV esophagoscopy to monitor whether the mucosa is broken or not, while assisting the intrathoracic dissection to free the smooth muscle tumor through endoscopic inflation, which is suitable for small tumor, no adhesion between tumor and mucosa and no adhesion in the thoracic cavity.
Some authors believe that for those who have large tumors with circular growth and serious adhesions with esophageal mucosa and those who have heavy damage to esophageal mucosa during surgery and have difficulty in repair, the scope of resection should be expanded and partial esophagectomy should be performed. If the tumor is malignant, partial esophagectomy should also be performed.
④Gastroesophageal partial resection is needed for huge esophageal smooth muscle tumor which is commonly found in the lower esophagus and can extend to the cardia or stomach, forming serious adhesions with the gastric mucosa and localized ulcers in the gastric mucosa. According to Seremitis’ analysis of 838 cases of esophageal smooth muscle tumors in 1976, partial gastroesophagectomy and GI reconstruction were required in about 10% of cases, and the main indications for surgery were
A. Multiple esophageal smooth muscle tumors or tumors with malignant transformation; B. Huge esophageal smooth muscle tumors combined with huge esophageal diverticula; C. Tumors involving the esophagogastric junction, and it is difficult to perform simple extra-mucosal tumor removal; D. Tumors forming dense adhesions with esophageal mucosa, and it is impossible to separate and remove the tumor from the mucosa.
Esophageal and gastric resection and reconstruction are suitable for those who have large and irregular tumors, which are not easily separated from the mucous membrane, some multiple smooth muscle tumors which are not easily removed, and those who are suspected of malignant changes and cannot exclude the possibility of malignant changes during surgery.
(2) Surgical methods
①For upper middle esophageal smooth muscle tumor, the right anterolateral incision can be used, i.e., the patient is placed in supine position with the right side of the back padded at 300°, and the patient enters the chest through the third or fourth intercostal space of the right chest, which can obtain satisfactory surgical exposure. If the posterior lateral dissection incision is chosen, consideration should also be given to which side of the esophagus the tumor is located. For lower esophageal smooth muscle tumor, the patient should be placed in the right lateral position and enter the chest through the 6th or 7th intercostal interval of the posterior lateral incision of the left chest. For partial gastroesophagectomy and intrathoracic gastroesophageal anastomosis, the standard left lateral dissection incision should be chosen. For smooth muscle tumors of the cervical esophagus, the patient should be placed in a supine position, and the tumor should be removed through a left (right) anterior oblique sternocleidomastoid incision to expose the cervical esophagus.
After removing the tumor into the chest, according to the location and size of the tumor, the mediastinal pleura should be cut longitudinally along the esophageal bed, and the tumor segment of esophagus should be bluntly freed, and a gauze strip should be used to lift the segment of esophagus, and the relationship between the tumor and the esophageal lumen (mucosa) and the mobility of the tumor in the esophageal wall should be palpated with fingers to avoid accidentally injuring the esophageal mucosa in most of the lesions when cutting the esophageal muscular layer and removing the tumor. Due to the long-term compression of the tumor, the muscle layer is thinned and the muscle fibers are loosened. The esophagus was appropriately rotated along the longitudinal axis of the esophagus so that the tumor was directly exposed in the surgical field and away from the esophageal lumen as much as possible. The tumor surface is then incised longitudinally through the esophageal epithelium and muscle layer to reveal the porcelain white smooth tumor. The tumor is separated using sharp and blunt dissection immediately adjacent to the tumor. If necessary, 1 to 2 stitches of No. 4 or No. 7 silk are used to traction through the tumor body to facilitate the freeing of the esophagus; the tumor can be completely removed after the complete separation of the esophageal muscle fibers, submucosal layer, mucosal layer and tumor envelope.
When freeing the tumor, the index finger and thumb of the left hand can be used to pinch the esophagus and the tumor and gently squeeze the tumor from the esophageal wall to the incision of the muscular layer, so that the boundary between the tumor and the surrounding tissues is clearer and the freeing is easier.
After removing the tumor from the esophageal muscle layer, if there is any suspicion that the esophageal mucosa may be damaged, the tip of the gastric tube can be pulled upward from the gastric cavity and placed at the level equivalent to the tumor bed in the esophageal cavity, and then the upper and lower ends of the esophageal trauma can be compressed with fingers, and saline can be injected into the surgical field. After that. If the esophageal mucosa of the tumor bed does not expand and bubbles escape outward from the lumen of the esophagus after air injection, it proves that there is damage to the mucosa of the tumor bed, and after confirming the damage site, the saline in the surgical field is aspirated, and the broken esophageal mucosa is repaired by suturing with small circular needle and fine silk or 5-0 absorbable suture.
If the tumor is large and the adhesion with esophageal mucosa is serious, a longitudinal resection of the esophageal mucosa that cannot be freed because of the adhesion with the tumor can be performed at the same time as the resection of the tumor, and then the mucosal defect of the tumor bed can be repaired with longitudinal sutures. Since the esophageal mucosa is more elastic and stretchable, longitudinal suturing of the mucosal incision after resection of the tumor will not cause narrowing of the esophageal lumen.
If there is a large mucosal defect in the tumor bed (mucosal bare area) after removal of the tumor, it can be reinforced by covering with diaphragmatic flap, pleural flap, omentum, intercostal muscle or pericardial piece to prevent complications caused by a large mucosal defect in the tumor bed. In general, removal of esophageal smooth muscle tumors without repair of the bare esophageal mucosa does not result in necrosis of the bare mucosa. The mucosal bare area was not repaired in any way. According to our own clinical experience, in cases where intraoperative esophageal mucosa damage was encountered, repairing the mucosal fissure followed by suturing the myotomy or covering and reinforcing it with a tipped diaphragm flap is of great significance in preventing postoperative esophageal mucosal fistula, and Nissen (1949) reported a case of esophageal smooth muscle tumor in a patient with the removal of Nissen (1949) reported a case of a patient with esophageal smooth muscle tumor in which a 10-cm-long mucosal tube (tubeofmucose) was locally formed after removal of the tumor and was repaired with a tipped lung tissue flap.
(3) Postoperative management of patients with esophageal smooth muscle tumor can be removed after the operation if the operation is successful and if the esophageal mucosa is not damaged during the removal of the tumor and the chest cavity on the operated side is not contaminated. On the first postoperative day, the patient is started on a liquid diet, which is changed to a semi-liquid diet on the third or fifth postoperative day. If the patient has undergone esophagectomy and gastroesophageal intra-thoracic anastomosis, the postoperative management is the same as that after esophagectomy.
The majority of patients who underwent extra-mucosal tumor removal for esophageal smooth muscle tumor recovered well without complications after surgery. However, if the esophageal mucosa is damaged during surgery and poorly repaired or if the damage to the mucosa is not detected, postoperative esophageal fistula can easily be complicated and cause serious consequences. In the case of small esophageal fistula, the fistula can be gradually healed by closed chest drainage, fasting, anti-infection and extra-gastrointestinal nutrition; in the case of large esophageal fistula, if detected early and the patient’s condition allows, the fistula should be repaired by thoracotomy or partial esophagectomy and intrathoracic gastroesophageal anastomosis.
After removal of large esophageal smooth muscle tumor, the local esophageal muscle layer is weak and scar adhesions occur, which may complicate esophageal luminal stenosis or pseudo esophageal diverticulum. Therefore, unnecessary surgical trauma should be avoided during surgery to reduce surgical trauma to the esophageal muscle layer at the tumor site and carefully repair the defect of esophageal wall. Patients with symptoms of dysphagia due to esophageal scar stenosis often need to perform esophageal dilatation.
Non-surgical observation: The development of this disease is slow, and although it has potential malignant tendency, the malignant rate is low. Therefore, for those who are old, have small tumors and have no obvious symptoms, they can be followed up without surgical treatment.
Complications
1. This disease is often accompanied by a number of concomitant diseases, including: esophageal cancer (there is no direct relationship between the two, because esophageal cancer is a common disease), esophageal hiatal hernia, diverticulum, esophageal hemangioma and cardia incontinentia.
2. Cases of esophageal smooth muscle tumor complicated by postoperative esophageal fistula, pulmonary infection, and anastomotic stricture have been reported, but the situation is usually easy to control.
To prevent the diagnosis of smooth muscle tumor, the possibility of esophageal malignancy must be considered for differential exclusion. Mucosal biopsy should not be performed during esophagoscopy to avoid damage and adhesions between mucosa and tumor, which may hinder later surgical removal. Surgery should be performed with good effect, less trauma and less complications than partial esophagectomy.