Laparoscopic resection of a large paraganglioma arising in the organ of Zuckerkandl: Report of a case and review of the literature.

Paragangliomas are catecholamine-secreting neuroendocrine tumours arising from chromaffin tissue at extra-adrenal sites. The commonest site for a paraganglioma is the organ of Zuckerkandl. Traditional treatment of paraganglioma of organ of Zuckerkandl (POZ) involves open surgical resection, and only a few cases of laparoscopic approach to this pathology have been reported. We report the successful laparoscopic resection of a large POZ in a 22-year-old woman and review the previous cases reporting a laparoscopic approach to this rare tumour.

INTRODUCTION

Extra-adrenal pheochromocytomas (EAPs), more accurately known as paragangliomas, are rare tumours that account for 10-25% of pheochromocytomas.[1] Some 53% of EAPs occur in the organs of Zuckerkandl,[1] which are a collection of paraganglia situated anterolateral to the distal abdominal aorta between the origin of the inferior mesenteric artery and the aortic bifurcation. The traditional treatment of a paraganglioma of organ of Zuckerkandl (POZ) involves open surgical excision, and only seven previous cases of laparoscopic resection have been reported [Table 1]. We describe successful laparoscopic resection of a large POZ in a young woman and review the previously reported cases.

Table 1

Cases of POZ reported in the literature and present case

CASE REPORT

A slender, 22-year-old woman with a body mass index (BMI) of 23 was being treated for hypertension for 2 years but it remained poorly controlled despite three antihypertensive drugs. She gave a history of intermittent episodes of sweating and palpitations. An abdominal ultrasound showed an 8 cm × 7 cm mass on the left side of the abdomen. A contrast-enhanced computed tomograph (CT) [Figure 1a] confirmed a vascular tumour lateral to the aortic bifurcation and extending along the left common iliac artery. Both the adrenals were normal. Haematological and biochemical investigations were normal except for grossly elevated plasma free normetanephrine and free metanephrine levels. A metaiodobenzylguanidine (MIBG) scan [Figure 1b] showed intense uptake in the area corresponding to the mass identified on the CT scan, but no other areas of uptake were identified. A work-up for multiple endocrine neoplasia type 2 (MEN2) was negative. Her preoperative preparation included a high-salt diet and alpha blockade with prazosin for 2 weeks, followed by beta blockade with propranolol for 1 week.

Figure 1

(a) CT scan showing a vascular tumour (arrow) adjacent to the aortic bifurcation (b) MIBG scan showing increased uptake in the area corresponding to the tumour identified on the CT scan

A laparoscopic excision was planned with the patient placed in the partial left lateral decubitus position. A 10-mm port was placed in the right iliac fossa for the telescope using an open entry. A 5-mm port was placed to the left side of this port, and another 5 mm port in the midline in the suprapubic area [Figure 2]. A steep Trendelenburg position allowed the small bowel and omentum to be moved away from the tumour, which was seen protruding through the descending and sigmoid mesocolon [Figure 3a]. A long horizontal incision was made in the anterior leaf of the mesocolon using an ultrasonic shears (Harmonic Scalpel, Ethicon Endo-surgery, Mumbai, MH, India). The inferior mesenteric artery lying posterior to the tumour was carefully separated from it and preserved. Multiple feeding vessels were clipped and divided [Figure 3b]. The well-encapsulated tumour was excised in toto. The mesocolic incision was closed with a running 2/0 polydiaxanone (PDS, Johnson and Johnson, Mumbai, India). The specimen was placed in a plastic bag and extracted through a 5-cm Pfannenstiel incision that incorporated the incision made for the suprapubic 5-mm port. Except for brief periods of hypertension during dissection of the tumour she remained stable throughout surgery. The total operative time was 125 min and intraoperative blood loss was around 40 mL. She was observed in the intensive care unit overnight, started on liquids and diet the day after surgery and discharged on post-operative day 4. The histopathology report confirmed the tumour to be a paraganglioma with no features of malignancy. She remains normotensive and off her antihypertensive medication at the 18-month follow-up, at the time of writing, and her CT scan and biochemical tests, repeated 1 year after the surgery, were normal.

Figure 2

Positions of the ports and the suprapubic 5-cm incision used for extraction of the specimen. Dotted circle denotes the position of the palpable tumour

Figure 3

(a) Large tumour protruding into the descending mesocolon (b) Vessel entering the tumour from the inferior mesenteric artery being clipped

DISCUSSION

Paraganglia are the main source of catecholamine production in the foetus and regress after 3 years of age.[9] Failure of chromaffin cells at the site of paraganglia to regress leads to the development of paragangliomas. The majority of the tumours occurring in the organ of Zuckerkandl are benign and non-functional, but malignant and functional tumours are known to occur at this site. Nearly half of the paragangliomas are familial and associated with neurofibromatosis type 1, MEN2, von Hippel-Lindau syndrome or hereditary paraganglioma syndrome.[2]

The symptoms of paragangliomas may be related either to excessive catecholamine secretion or pressure symptoms due to a retroperitoneal mass. Headache, fainting and dizziness with hypertension are common with norepinephrine-producing tumours, whereas those secreting epinephrine tend to produce irritability, tachycardia, diarrhoea, excessive sweating, flushing and possibly hypertension. Yadav et al. reported a paraganglioma producing ureteral obstruction,[10] whereas Blecha et al. described one causing small-bowel obstruction.[11] Plasma free metanephrines and urinary fractionated metanephrines carry the highest sensitivity (99% and 97%, respectively) compared to the other plasma or urinary metabolites.[12] Imaging studies allow assessment of the location, extent and multifocality of the disease. A CT scan is usually the first imaging test performed but may not identify lesions smaller than 2 cm. A magnetic resonance imaging (MRI) scan has higher sensitivity and specificity in detection of paragangliomas, which appear hyperintense on T2-weighted sequences.

Alpha blockade (with phenoxybenzamine or prazosin) followed by beta blockade (with propranolol or a cardio-selective beta blocker) as well as adequate hydration are crucial in the preoperative preparation of POZ. Close intraoperative haemodynamic monitoring and control of hypertensive or hypotensive episodes that may occur by an experienced anaesthetist allows the surgery to proceed smoothly. Surgical resection is the treatment of choice for POZ, and laparoscopic resection is suited for small (<7 cm) tumours that show no radiological signs of invasion. Only seven cases of laparoscopic resection of POZ have been previously described.[2345678] Depending on their location, strategies utilised to approach the tumour included duodenal Kocherisation as well as colonic mobilisation. Only Thaper et al. described a mesocolic approach similar to ours, but they utilised three 10-mm ports, one sited at the umbilicus and the others on the left side of the abdomen.[4] In our patient we chose to place the 10-mm camera port in the right iliac fossa to allow direct, end-on visualisation of the tumour. The original plan of colonic mobilisation to approach the POZ was modified to a transmesocolic approach once it was apparent that this would provide early access to the tumour vasculature arising from the aorta and inferior mesenteric artery. Early control of these vessels minimised intraoperative haemodynamic instability. The left ureter and the inferior mesenteric artery are structures that need to be safeguarded during resection of a POZ, although on occasion the latter may have to be resected.[58] In rare instances of malignant POZ invading the aorta or the inferior vena cava, open resection and reconstruction of these vessels as reported by Dossett et al. may be warranted.[13] Extraction of the specimen in a plastic bag via a low Pfannenstiel incision resulted in a cosmetic scar in our young patient.

Histopathological examination alone does not accurately differentiate benign and malignant paragangliomas, and the diagnosis of malignancy is based on the presence of local invasion and/or presence of metastases. Subramanian et al. in a collective review of 135 cases of POZ found 41% to be malignant.[14] In view of this, long-term follow-up with annual clinical, biochemical and radiological evaluation is mandatory in all patients with POZ. In case of local recurrence, surgery remains the mainstay in those amenable to it. However, palliative therapy in the form of iodine-131 (131 I)-MIBG may have to be resorted to if the tumour is unresectable or metastatic.

CONCLUSION

In conclusion, POZ is a rare tumour that can be resected safely laparoscopically by experienced surgeons. Adequate preoperative preparation, careful intraoperative management as well as post-operative care form the cornerstones of successful outcome in these patients.

Financial Support and Sponsorship

Nil.

Conflicts of Interest

There are no conflicts of interest.