Esophageal fistula after resection of giant mediastinal liposarcoma: A case report

Abstract

BACKGROUND

Liposarcoma is the most common soft tissue tumor in adults. Liposarcoma commonly occurs in the lower extremities and retroperitoneum but rarely in the mediastinum. To the best of our knowledge, this is the first report of bilateral single-port video-assisted thoracoscopic surgery (VATS) for giant mediastinal liposarcoma and the first report of esophageal fistula after this surgery.

CASE SUMMARY

We present the case of a 71-year-old male patient with a giant posterior mediastinal tumor. Chest computed tomography and magnetic resonance imaging showed that the tumor completely involved the esophagus. The patient underwent bilateral single-port VATS and the tumor was completely removed. An esophageal fistula was detected 9 days after surgery and 2 days after eating. Emergency debridement surgery was performed, and a drainage tube was placed. The fistula healed gradually after the second surgery.

CONCLUSION

VATS is safer than thoracotomy for treating giant mediastinal liposarcoma. For tumors extensively involving the esophagus, preventive measures against esophageal fistula are necessary.

Key Words: Liposarcoma; Mediastinum; Bilateral single-port video-assisted thoracoscopic surgery surgery; Esophageal fistula; Case report

Core Tip: We report a very rare case of giant mediastinal liposarcoma. To the best of our knowledge, this is the first report of bilateral single-port video-assisted thoracoscopic surgery for giant mediastinal liposarcoma and the first report of esophageal fistula after this surgery. This report provided valuable lessons and reference for selection of appropriate surgical approach and the management of postoperative esophageal fistula.

INTRODUCTION

Mediastinal soft tissue tumors are very rare, accounting for 2%-6% of mediastinal malignancies[1]. Liposarcoma is the most common soft tissue tumor in adults[2] and commonly occurs in the lower extremities and retroperitoneum[3]. There are four histologic sub-types of liposarcoma: Myxoid, well differentiated, dedifferentiated, and pleomorphic[4]. Liposarcomas account for only about 0.1%-0.75% of mediastinal tumors[5,6], and the most common histologic sub-type in the mediastinum is well-differentiated tumor[3]. Well-differentiated liposarcoma is also called atypical lipomatous tumor (ALT)[7].

Surgery remains the first-choice treatment for mediastinal ALTs[2]. However, ALTs may cause only minimal symptoms and tend to be large when clinically detected because of their slow-growing nature[8]. Huge ALTs often occupy both sides of the chest cavity and invade the esophagus. Thus, selection of appropriate surgical approach is very important. Median sternotomy or clamshell thoracotomy is the most common surgical approach[3,5].

In the present case, we successfully resected a giant posterior mediastinal ALT involving the esophagus during bilateral single-port video-assisted thoracoscopic surgery (VATS). The patient suffered from esophageal fistula 9 days after surgery and 2 days after eating. To the best of our knowledge, this is the first report of bilateral single-port VATS for giant mediastinal liposarcoma and the first report of esophageal fistula after this surgery. We present our experience with choosing the surgical approach and managing complications.

CASE PRESENTATION

Chief complaints

A 71-year-old male patient presented to the hospital complaining of a giant mediastinal mass, revealed by a computed tomography (CT) scan.

History of present illness

The mass was discovered by CT scan during a routine examination, and the patient had no symptom.

History of past illness

The patient had a history of hypertension and took amlodipine besylate tablets 5 mg qd. The patient was a smoker with 30 pack-years.

Personal and family history

The patient was healthy and had no personal or family history of tumors.

Physical examination

The patient presented mild coarse breath sounds in the right upper lung during auscultation.

Laboratory examinations

Laboratory tests revealed an increased percentage of neutrophilic leukocytes (78.4%) with normal hematocrit and platelet count values. Tumor markers such as carcinoembryonic antigen, Carbohydrate antigen (CA) 199, CA125, neuron-specific enolase, and cytokeratin fraction 21-1 were all in the normal range.

Imaging examinations

Contrast-enhanced CT scan showed a giant posterior mediastinal tumor with a fatty component (Figure 1A). The mass completely involved the esophagus and descending aorta. The heart and lower lobes of both lungs were deviated anteriorly by the tumor. Giant mass with variable proportions of fat, soft tissue, and myxoid tissue, these imaging features of the tumor were suggestive of well-differentiated liposarcoma. Positron emission tomography showed no distant metastasis.

Figure 1 Enhanced computed tomography scan and chest enhanced magnetic resonance imaging. A: Showing a giant posterior mediastinal tumor with a fatty component; B: Showing the tumor extensively involving the esophagus. There was still a small gap between the tumor and the esophagus.

FINAL DIAGNOSIS

The final diagnosis for this patient was well-differentiated liposarcoma and esophageal fistula after surgery.

TREATMENT

First surgery

According to the inspection results, surgical resection was indicated. The biggest issue is determining the surgical approach. Enhanced magnetic resonance imaging of the chest showed the tumor completely involved the esophagus. However, there was still a small gap between the tumor and esophagus (Figure 1B). To avoid accidental damage to the esophagus, a nasogastric tube was placed before surgery.

Given the unusual size and location of the tumor, a bilateral single-port VATS approach was selected. The size of the port was 40 mm. The patient was initially placed in the left lateral position, and the tumor in the right thoracic cavity was dissected by the single-port video-assisted thoracoscopic approach (Figure 2). The esophagus was peeled off from the tumor at the same time. Then, we turned the patient over, and the left tumor was also dissected by the single-port video-assisted thoracoscopic approach. The huge tumor was finally removed from the thoracic cavity piece by piece. A specimen bag was used to prevent tumor dissemination in the chest cavity. The tumor measured 30 cm × 19 cm × 5 cm.

Figure 2 Surgical incisions for the bilateral single-port video-assisted thoracoscopic surgery.

Pathological examination demonstrated well-differentiated liposarcoma, and Fluorescence in situ hybridization examination indicated amplification of murine double minute 2 (Figure 3).

Figure 3 Hematoxylin and eosin staining showing atypical spindle-shaped cells in the tumor (original magnification × 100).

Esophageal fistula after surgery

The patient was fasting from solids and liquids during the first week after surgery. On the seventh day after surgery, the patient underwent a CT scan after taking iopamidol orally. The scan showed no leakage of contrast agent. Then, the patient started to eat liquid food.

Unfortunately, an esophageal fistula combined with mediastinitis and empyema was detected 9 days after surgery and 2 days after eating. Emergency debridement surgery was performed with VATS using the same port of the first surgery, and a drainage tube was placed (Figure 4). After surgery, the patient was fasting from solids and liquids again and nutrient solution was feeded through a nasogastric tube. We rinsed the thoracic cavity with physiological saline and sodium bicarbonate every day via the drainage tube, and the fistula healed gradually (Figure 5).

Figure 4 Computed tomography scan showing an esophageal fistula combined with mediastinitis and empyema. Emergency debridement surgery was performed.

Figure 5 Computed tomography scans showing gradual healing of the fistula after emergency debridement surgery.

OUTCOME AND FOLLOW-UP

Two months after the second surgery, gastroscopy was performed to confirm the fistula had totally healed, and the patient was discharged. Two weeks after the patient get home, he was able to eat normally. Six months after surgery, the patient underwent a CT scan, and there was no evidence of local recurrence.

DISCUSSION

Liposarcomas arising within the mediastinum are quite uncommon tumors, accounting for only about 0.1%-0.75% of mediastinal tumors[5,6]. The mean age of the patients was 52.6 ± 17.4 years reported in references and there was no sex predilection in these cases[6]. The World Health Organization histopathologic classification includes four distinct types of liposarcomas: Myxoid, well differentiated, dedifferentiated, and pleomorphic[4]. Although mediastinal liposarcoma is extremely rare, all four types can arise within the mediastinum[1].

ALT is the most common histologic sub-type of mediastinal liposarcoma, accounting for approximately 40% of all liposarcomas[9]. ALTs usually grow slowly and insidiously, and remain asymptomatic until reaching a huge size[2]. Berry et al[10] and Klimstra et al[11] reported that the average size of mediastinal liposarcomas is 15.7 cm, ranging from 6 cm to 40 cm, and the average weight is 1.5 kg. As liposarcoma is not sensitive to chemotherapy or radiotherapy, complete surgical resection using the standard median sternotomy or lateral thoracotomy is the most employed therapeutic choice[2,12]. Since the tumor is usually huge and compresses intrathoracic organs, such as the heart, great vessels, lungs, and esophagus[2], VATS is seldom reported as the treatment for mediastinal liposarcoma. In our case, the tumor was huge, occupied both sides of the chest cavity, and completely involved the esophagus. Minimally invasive surgery seemed impossible for this patient. However, according to enhanced chest magnetic resonance imaging, a small gap was still present between the tumor and esophagus. As VATS has a clear surgical field of view, we tried a bilateral single-port VATS approach, which has never been reported before. During the operation, the boundary between the tumor and the esophagus was clearly visible on the video, and the huge tumor was finally removed completely. The magnifying effect and clear surgical field of view seem to make VATS safer than thoracotomy.

Esophageal fistula after resection of a giant mediastinal tumor has not been reported in the literature before. As the tumor extensively involved the esophagus in the present case, measures were taken to prevent the occurrence of esophageal fistula. A nasogastric tube was placed before the first surgery, and the patient was fasting from solids and liquids during the first week after surgery. Before eating, the patient underwent a CT scan after taking iopamidol orally, and the scan showed no leakage of contrast agent. However, esophageal fistula still occurred after the patient ate. By reviewing the surgical video, we confirm that there was no direct damage to the esophageal wall during the surgery. We believe that the cause of the esophageal fistula was ischemia after peeling the esophagus from the tumor. Extensive periesophageal dissection, especially during resection of large, adherent tumors, can impair blood flow to the esophageal wall, leading to tissue necrosis and fistula formation. Fasting for a longer period may help prevent esophageal fistula.

Esophageal fistula after surgery is associated with high rates of mortality[13]. Thus, early identification and management of esophageal fistula are extremely important. The therapy for esophageal fistula includes controlled drainage, nil per os, and antibiotics administration[14]. In the case of mediastinitis or empyema, surgical debridement is used[14]. In our case, mediastinitis and empyema were both diagnosed by CT scan, so emergency debridement surgery was performed, and a drainage tube was placed. Endoscopic placement of an esophageal stent was associated with anastomotic leak treatment efficiency of 72%[14]. However, a 2011 study warned that endoscopy may exacerbate anastomotic defects and mediastinal contamination during endoscopy[15]. Patients with extensive devitalization of the esophagus are not suitable for endoscopic stenting[15]. Thus, in our case, esophageal stent placement was not recommended. We rinsed the thoracic cavity with physiological saline and sodium bicarbonate every day via a drainage tube. We believe that sodium bicarbonate could create an alkaline environment, inhibiting bacterial growth.

CONCLUSION

To the best of our knowledge, this is the first report of bilateral single-port VATS for giant mediastinal liposarcoma, and the first report of esophageal fistula after this surgery. The magnifying effect and clear surgical field of view make VATS safer than thoracotomy. For tumors extensively involving the esophagus, fasting for a longer period may help prevent the occurrence of esophageal fistula. Early identification and management of esophageal fistula are very important. Surgical debridement, controlled drainage, nil per os and antibiotic therapy are the main treatments for esophageal fistula.

ACKNOWLEDGEMENTS

We are grateful to the patient for his agreement of publication of this report and accompanying images.