Laparoscopic Resection of Subclinical Functioning Para-aortic Paraganglioma

Introduction:

Extra-adrenal pheochromocytomas (paragangliomas) are neuroendocrine tumors derived from extra-adrenal chromaffin cells. Although laparoscopic resection of adrenal pheochromocytomas is a common procedure, there are few reports of the use of this approach in extra-adrenal para-aortic paragangliomas. Here, we report the case of a patient with a subclinical functioning para-aortic paraganglioma that was successfully resected laparoscopically.

Case presentation:

A 58-year-old man was referred to our department for treatment of a para-aortic tumor after endoscopic submucosal dissection of early-stage colorectal cancer. Positron emission tomography-computed tomography showed abnormal accumulation by the para-aortic tumor. During its laparoscopic resection, the patient's blood pressure unexpectedly rose to over 180 mmHg, which suggested that the tumor was a paraganglioma. The diagnosis was confirmed by immunohistochemical staining, which showed chromogranin-positive cells forming a Zellballen pattern. The operation was successfully completed, and the patient's postoperative course was uneventful.

Conclusion:

Laparoscopic resection may be a suitable procedure for the treatment of retroperitoneal paraganglioma.

Retroperitoneoscopic resection of primary paraganglioma: single-center clinical experience and literature review

BACKGROUND AND PURPOSE

Paraganglioma (PG) is a rare neuroendocrine entity. Surgical resection is recommended as the mainstay of treatment due to the uncontrolled hypertension, close proximity to major vessels, variable location, and higher potential malignancy. With rapid development of minimally invasive techniques during the past decade, laparoscopic resection of retroperitoneal PG has been reported with successful results. There are only a few publications describing retroperitoneal access, however. In the present study, we proposed to summarize our experience on retroperitoneal laparoscopic resection in 10 patients and systematically review relevant publications to evaluate its safety and efficacy.

PATIENTS AND METHODS

From June 2009 to October 2013, 10 patients with PG who were treated with retroperitoneoscopy were included in the study. Minimal effective dosage α-blockade with phenoxybenzamine was routinely used. Preoperative, intraoperative, and postoperative baseline data were collected and analyzed. Meanwhile, two reviewers independently searched and identified 8 retrospective studies and 23 case reports in the Medline, Embase, and Science Citation Index between 1998 and 2013.

RESULTS

Operations in 9 of 10 patients were successfully completed without conversion; one case was converted to open surgery because of left accessory renal artery injury. Mean operative time, blood loss, and postoperative hospital stay were 97.8±20.6 minutes, 44.4±8.2 mL, and 4.8±3.5 days, respectively. There were three complications in this series, including accessory renal artery injury, renal vein injury, and chylorrhea.

CONCLUSIONS

Retroperitoneoscopic resection is feasible, effective, and safe in the treatment of patients with PG according to our preliminary clinical experience and has distinct advantages including direct access to the tumor, less intraperitoneal interference, precise dissection, and minimal invasiveness.

Abdominal Paragangliomas: Analysis of Surgeon's Experience

Abdominal paraganglioma is a rare endocrine tumor associated with genetic mutations, however, the ability to predict long-term risk of metastasis has not been clarified. The aim of this study was to examine the clinicopathological features and outcomes in patients undergoing surgery for an abdominal paraganglioma. A retrospective analysis was performed for all patients undergoing surgery for abdominal paragangliomas from one surgical department between 1998 and 2010. Clinical presentation, hormone secretion and clinical outcomes were examined. A total of 23 patients underwent surgery for abdominal paraganglioma with the most common presentation being hypertension. Median time to metastasis was 32 months with all patients developing disease progression having a rise in urine catecholamines. Patients with capsular invasion or predisposing genetic conditions are at a higher risk of having more aggressive disease. All patients with a diagnosis of paraganglioma should be screened for predisposing genetic abnormalities and postoperative follow-up must include routine urinary catecholamine assessment.

Extra-adrenal pheochromocytoma: Diagnosis and management

Extra-adrenal pheochromocytomas (EAPs) may arise in any portion of the paraganglion system, though they most commonly occur below the diaphragm, frequently in the organ of Zuckerkandl. EAPs probably represent at least 15% of adult and 30% of childhood pheochromocytomas, as opposed to the traditional teaching that 10% of all pheochromocytomas are at extra-adrenal sites. They may be malignant in up to 40% of the cases, though conflicting data add to the uncertainty of this point. Patients with EAPs may present with headache, palpitations, sweating, or hypertension. A small percent of patients may also be asymptomatic at presentation due to nonfunctional tumors. The diagnosis is confirmed by demonstrating elevated blood and urine levels of catecholamines and their metabolites. Imaging studies to evaluate for EAPs include CT, MRI, and (131)I-labelled metaiodobenzylguanidine scintigraphy. Preoperative pharmacologic preparation, attentive intraoperative monitoring, and aggressive surgical therapy have important roles in achieving successful outcomes. Recent reports suggest that a laparoscopic approach, along with intraoperative ultrasound, can safely remove these tumors. EAPs recur and metastasize more often than their adrenal counterparts, making lifelong follow-up essential.