Precision en-bloc retroperitoneal paraganglioma resection performed laparoscopically: A case report

Abstract

BACKGROUND

Phaeochromocytoma and paragangliomas (PPGL) are rare neuroendocrine tumors usually caused by parasympathetic or sympathetic nerves, with an overall incidence of approximately 0.66 cases per 100000 people per year. Most PPGLs are asymptomatic, and a few develop symptoms, such as elevated blood pressure and rapid heart rate, because of the release of catecholamines. According to the literature, surgical resection is the mainstay of PPGL treatment. However, the choice between minimally invasive surgery and open surgery remains controversial, particularly in cases involving complex anatomical relationships. We successfully resected a tumor located between the inferior vena cava and abdominal aorta using a minimally invasive approach with the assistance of computed tomography (CT) angiography and three-dimensional reconstruction, resulting in a favorable outcome.

CASE SUMMARY

A 56-year-old woman was admitted to the hospital with right upper abdominal discomfort for more than 6 months, experiencing occasional pins and needles sensation and radiation from the right shoulder and back. Prehospital CT of the upper abdomen revealed a retroperitoneal mass suspected to be a retroperitoneal ganglioneuroma. Surgery was recommended, and an enhanced CT scan of the upper abdomen, along with preoperative three-dimensional reconstruction, was performed after admission. The imaging indicated that the mass, measuring approximately 4.1 cm × 3.8 cm × 4.8 cm, was situated between the abdominal aorta and the inferior vena cava, extending downward to the level of the left renal vein. After ruling out any contraindications to surgery, a minimally invasive laparoscopy was performed to excise the mass precisely. The surgery was successful without any postoperative complications, and the 2-month follow-up revealed no abnormal signs of recurrence.

CONCLUSION

This case report describes successful and precise laparoscopic resection of a retroperitoneal tumor. The patient recovered well during the 2-month follow-up, and postoperative pathology revealed a paraganglioma.

Key Words: Pheochromocytomas; Paragangliomas; Treatment; Laparoscopic; Case report

Core Tip: The surgical resection of retroperitoneal paragangliomas (PGL) is widely acknowledged as the most effective therapeutic approach. Surgical methods are primarily divided into laparoscopic and traditional open surgeries. Although there is some debate regarding the choice between these two surgical modalities, laparoscopic surgery has become the preferred method for the excision of such tumors because of its minimally invasive nature. Compared with open surgery, the increased risk of significant trauma and postoperative complications cannot be overlooked. In this case, with the aid of advanced imaging technology, we successfully performed laparoscopic resection of a PGL in an anatomically complex region, achieving satisfactory therapeutic outcomes. This study provides new perspectives on the use of laparoscopy to address complex PGLs.

INTRODUCTION

Paragangliomas (PGLs) are rare neuroendocrine tumors that typically originate in the parasympathetic or sympathetic nerves. Because the parasympathetic nerves are mainly located in the head and neck region, whereas the sympathetic nerves are primarily found in the abdomen, PGLs can be distributed widely throughout the body. Furthermore, because sympathetic nerves are primarily concentrated in the adrenal medulla, the World Health Organization classifies pheochromocytomas of adrenal medullary origin as intra-adrenal PGLs, collectively known as phaeochromocytoma and PGL (PPGL)[1-3]. In clinical practice, distinguishing PPGL from other diseases presents significant challenges owing to its rarity and diverse symptoms. This can lead to underdiagnosis and misdiagnosis, potentially impacting subsequent treatments[4]. Surgical resection remains the most effective treatment for PPGL[5]. The decision to use minimally invasive laparoscopic or open surgical approaches for PPGL is controversial, given the tendency of PPGL tumors to develop near vital tissues and organs, such as major blood vessels. In this case report, we detail laparoscopic surgery and precise resection facilitated via preoperative three-dimensional (3D) reconstruction and enhanced computed tomography (CT) in a patient with PPGL. This method confirmed the safety and efficacy of a minimally invasive procedure, contributing to a positive prognosis.

CASE PRESENTATION

Chief complaints

A 56-year-old woman presented to our hospital with a 6-month history of upper right abdominal discomfort.

History of present illness

The patient was admitted to the hospital with right upper abdominal discomfort for more than 6 months, occasional pins and needles sensation, and a radiating sensation in the right shoulder and back. Prehospital CT of the upper abdomen revealed a retroperitoneal space, which was suspected to be a neurogenic lesion such as a PGL.

History of past illness

The patient was in good health, with no history of heart disease, respiratory disease, hypertension, or psychiatric illness. Additionally, there was no history of hepatitis, tuberculosis, syphilis, or other infectious diseases. The patient had been dealing with type 2 diabetes mellitus for 5 years, but her blood glucose levels were not regularly monitored. The patient was treated with oral metformin and exhibited fair glycemic control. There were no records of blood transfusions, drug allergies, food allergies, dust allergies, or allergies to other substances. Furthermore, there was no history of chronic smoking, alcohol consumption, or a family history of the disease.

Personal and family history

No family history of disease.

Physical examination

There were no symptoms of fever, vomiting, bloating, or diarrhea upon admission. Physical examination revealed no abnormal elevation or depression of the abdominal wall and no gastrointestinal pattern or peristaltic waves. Bowel sounds were 4 beats per minute. Tenderness was noted in the right upper abdomen; however, the abdomen was not palpated, and Murphy’s sign was negative.

Laboratory examinations

Laboratory tests revealed no abnormalities in blood, coagulation, electrolytes, liver, or renal function. Adrenocorticotropic hormone levels were mildly elevated (66.5 pg/mL), and aldosterone (prone) was mildly decreased at 34.7 pg/mL. Plasma and urine catecholamine and cortisol levels were normal. Furthermore, electrocardiography, chest CT examination, and 24-hour ambulatory blood pressure monitoring were all within normal limits.

Imaging examinations

CT and 3D reconstruction of the upper abdomen revealed a slightly less dense shadow in the retroperitoneum [between the abdominal aorta and the inferior vena cava (IVC)], measuring approximately 4.1 cm × 3.8 cm × 4.8 cm, with well-defined borders and regular morphology. The IVC narrowed because of forward compression, with no evidence of compression of the abdominal aorta. Enhanced scanning did not show any significant enhancement (Figures 1 and 2).

Figure 1 Preoperative three-dimensional reconstruction shows the mass in relation to the adjacent vital vessels. IVC: Inferior vena cava; AA: Abdominal aorta; LRV: Left renal vein; HV: Hepatic vein; PV: Portal vein.

Figure 2 Upper abdominal computed tomography scan. A: Non-contrast phase; B: Arterial phase; C: Hepatic venous phase; D: Portal venous phase. Yellow arrows indicate the mass, white arrows point to the inferior vena cava, and black arrows highlight the abdominal aorta.

FINAL DIAGNOSIS

The final diagnosis of this patient was retroperitoneal PGL, which was determined based on intraoperative and postoperative pathological findings.

TREATMENT

Initially, the patient was administered general anesthesia and placed in the reverse Trendelenburg position. Five trocars were used to facilitate this procedure. After establishing CO₂ pneumoperitoneum, the abdominal cavity was first explored using a laparoscope. A Kocher incision was used to effectively release the duodenum and locate the precise position of the mass between the abdominal aorta and IVC. This approach also facilitated examination of the interrelations among the structures of the pancreatic head, IVC, abdominal aorta, and left renal vein (LRV) in relation to tumors with or without tumor invasion. The mass was carefully dissected along the lateral aspect of the IVC, above the LRV, and along the lateral aspect of the duodenum, using an ultrasonic knife. The tumor and trophoblastic vessels were ligated. Stripping was continued until the mass was completely separated from the surrounding tissue and the tumor was completely resected. For detailed procedural steps of the surgery, please refer to Video 1. The operation was completed within 180 minutes, with an estimated blood loss of 50 mL. The proximity of the mass to the vital organs and large blood vessels increased the complexity of the operation. However, there were no complications, such as hemorrhage, and the patient was discharged without any postoperative complications.

OUTCOME AND FOLLOW-UP

Postoperative pathological examination revealed a mass consistent with the biological characteristics of a peritoneal ganglioneuroma. Subsequent follow-up for 2 months did not reveal any abnormalities or recurrences. This case report was published after informed consent was obtained from the patient and her family.

DISCUSSION

PPGL is a rare neuroendocrine tumor with an incidence of approximately 2%-8%. In the abdomen, the majority of PPGLs originate in the chromaffin cells of the adrenal glands, and these tumors are called pheochromocytomas. Comparatively, approximately 10%-20% of PPGLs originate in the sympathetic nervous system and are called PGLs. Despite their different origins, they are collectively referred to as PPGL. Patients with pheochromocytomas may present with persistent or paroxysmal elevation of blood pressure, as well as intermittent flushing and palpitations[6,7], whereas those with PGL tend to be asymptomatic, making diagnosis more challenging.

Currently, surgical resection is the only curative treatment for PPGL. There are two main types of surgery: Open and laparoscopic. In recent years, laparoscopic surgery has become the preferred option for the treatment of PPGL owing to its minimally invasive nature. Moreover, it ensures complete tumor resection, and its efficacy is comparable to that of open surgery. Additionally, it reduces surgical trauma, promotes wound healing, and accelerates recovery. However, open surgery is still necessary for larger, more aggressive, or difficult-to-operate PPGL to ensure complete tumor resection, prevent intraoperative tumor rupture, and reduce the risk of local recurrence[8,9].

In this case, laparoscopic surgery may have led to severe intraoperative bleeding because of the special location of the patient’s tumor, which was adjacent to the abdominal aorta and IVC. Toutounchi et al[10] found that more than half of their patients underwent open access because of difficult or complicated tumor locations. Tumors located near the abdominal aorta and IVC are prone to injuring large vessels owing to their short blood supply, making hemostasis challenging, especially in laparoscopic surgery. In contrast, Abe et al[11] discovered that laparoscopic tumor resection, combined with preoperative 3D reconstruction, is feasible for safe and complete tumor removal. They studied 24 patients with PPGL who underwent surgery around the abdominal aorta and IVC. However, the long-term results require further investigation because of the small sample size and limited follow-up time. Despite this, considering the patient’s specific situation and preferences, we opted to perform laparoscopic surgery. Prior to the operation, we utilized advanced imaging techniques such as 3D reconstruction and CT angiography to obtain detailed information about the spatial relationship between the tumor and surrounding structures, particularly their positions relative to the IVC, LRV, and abdominal aorta. This information is crucial for precise intraoperative dissection and safe tumor resection, enabling the surgical team to anticipate potential obstacles and develop appropriate response strategies. Additionally, we must consider that a small number of patients with PPGL experience serious complications such as hypertensive crisis, tachycardia, and arrhythmia during surgery owing to tumor stimulation. This can result in a massive release of catecholamines, leading to catecholamine storms. Tumor resection can also cause severe hypotension because of a sudden drop in catecholamine levels[12]. Therefore, perioperative management and monitoring are crucial. Administering non-selective α and β adrenergic receptor antagonists before surgery can help manage and monitor these patients. Preoperative administration of non-selective α and β adrenergic receptor antagonists, calcium channel blockers, and/or catecholamine synthesis inhibitors can control the effects of catecholamines on cardiovascular tissues. In cases of severe hypotension post-surgery, stabilizing the patient’s vital signs can be achieved through intravenous fluids and a high-salt diet[13]. Ultimately, it is important to ensure that the surgery is successful.

CONCLUSION

PGLs are rare tumors, and those occurring in the retroperitoneum are even rarer. Surgical resection remains the preferred approach. Adequate preoperative preparation and understanding of the anatomical relationships are essential when treating such patients. The tumor in this case was situated between the abdominal aorta and the IVC, which complicated and increased the risks of surgery. Given the patient’s condition and the disadvantages of open surgery, we precisely localized the tumor using enhanced CT and 3D reconstruction. We then successfully excised the tumor completely via minimally invasive laparoscopic surgery. This successful case underscores the potential for extending the indications for laparoscopic resection of PPGL and provides a valuable reference for other scholars in selecting surgical options.

ACKNOWLEDGEMENTS

During the preparation of this manuscript, I express my sincere gratitude to Chengdu Medical College and Neijiang First People’s Hospital for providing a supportive research environment and valuable resources. I appreciate the collaboration of the surgical team members as well as the cooperation and trust of the patients and their families.