Aberrent Thoracic Duct Cyst in Postrior Mediastinum

A case of a thoracic duct cyst extending from the mediastinum to the cisterna chyli resected using bilateral thoracoscopic surgery in the prone position

BACKGROUND

Thoracic duct cysts are extremely rare mediastinal tumors. We report a case of a thoracic duct cyst extending from the caudal aspect of the left main bronchus to the left renal artery that was safely and completely resected via bilateral thoracoscopic surgery in the prone position.

CASE PRESENTATION

A 77-year-old male was referred to our hospital for follow-up computed tomography (CT) of prostate cancer, which revealed a mediastinal tumor and fatty low-density along the posterior mediastinum of the para-aortic artery with a slightly high-density component. Magnetic resonance imaging revealed a T2-weighted image with high intensity. The preoperative radiological diagnosis was lipoma or well-differentiated liposarcoma. CT in the prone position suggested that the tumor could be resected from the thoracic cavity to the caudal side, and bilateral thoracoscopic surgery was performed in the prone position. Based on the surgical findings, the tumor was diagnosed as a thoracic duct cyst rather than a lipoma. Dissection around the thoracic duct cyst was performed using a vessel-sealing system to prevent leakage of the chyle, and reliable clipping was performed to resect the cisterna chyli. Histopathological examination revealed smooth muscle structures around the cyst, suggestive of a thoracic duct cyst. The diagnosis of a thoracic duct cyst was made based on a high triglyceride level of 1310 mg/dL on examination of the milky-white cyst fluid. The patient's postoperative course was uneventful, and he was discharged 4 days postoperatively. A CT scan performed 13 months after surgery showed no recurrence.

CONCLUSIONS

A rare thoracic duct cyst extending from the mediastinum to the cisterna chyli was safely and completely resected using bilateral thoracoscopic surgery, with the patient in the prone position.

Chylopericardium following thoracoscopic resection of a mediastinal cyst: A case report

INTRODUCTION

Thoracic duct cysts are very rare, and diagnosis is often difficult. We report a rare case of chylopericardium following thoracic duct cyst resection. There are no established guidelines on the management of such cases. We reviewed the literature on postoperative complications after thoracic duct cyst resection, and conducted the first thorough review of the etiology and management of chylopericardium in surgical cases.

PRESENTATION OF CASE

A 54-year-old male presented with cardiac tamponade due to chylopericardium. He had undergone resection of a thoracic duct cyst 2 years previously, which was complicated by postoperative chylothorax. Chyle accumulation resolved with conservative treatment.

DISCUSSION

Chylothorax is a frequent complication following thoracic duct cyst resection, especially in cases where no intraoperative diagnosis is reached. Diagnosis may be difficult due to anomalous location of the cyst, as in our case. Chylopericardium is rarely reported, and may have occurred in our case because of prior pleurodesis. Chyle accumulation can reportedly be managed with diet restrictions in over half of reported cases, especially in cases of lung or mediastinal tumor resection.

CONCLUSION

The most important points highlighted by this rare case of chylopericardium secondary to thoracic duct cyst resection are: 1) pedicles should be ligated in cyst resections, regardless of location; 2) careful assessment in the initial surgery may help identify the point of leakage; 3) low-fat diet is the first choice in the initial management of postoperative chylopericardium, but surgical repair may be considered in cases with no response after>2 weeks of conservative treatment.