Laparoscopic adrenalectomy for ganglioneuroma presenting as an adrenal incidentaloma.

Adrenal incidentaloma (AI) has now become a common finding in clinical practice with advances in abdominal imaging. The prevalence of AI as reported in the literature is 0.2%-3%. Ganglioneuroma (GN) is often a benign non-functioning adrenal tumour, which has been rarely reported as AI in literature. Confirmed diagnosis of GN can only be done by histopathological examination. GNs are often asymptomatic even if they are large, and adrenalectomy is treatment for GN, with good prognosis after surgical removal. Here, we report a patient with an incidental adrenal mass that was managed laparoscopically and diagnosed as an adrenal GN on histopathology.

INTRODUCTION

Adrenal incidentalomas (AIs) are being increasingly diagnosed with evolution of abdominal imaging techniques. These tumours include a wide spectrum of lesions, including non-secreting adenomas, subclinical secreting tumours, various other benign lesions and malignant adrenocortical carcinomas. The incidental finding of an adrenal gland mass involves planning of a series of specific exams to define the malignant potential and any potential hormonal secretion.[1] The prevalence of AI as reported in the literature is 0.2% in young patients and 3% in populations past their fifth decade.[2] Surgical resection is required for large/atypical or secreting lesions because they are more likely to be malignant or cause symptoms.[3] Over the last 20 years, minimally invasive adrenal surgery has become the standard operation for removing the majority of benign adrenal masses.[4] We report a patient with an incidental adrenal mass that was managed laparoscopically and diagnosed as an adrenal ganglioneuroma (GN) on histopathology.

CASE REPORT

A 44-year-old female patient without significant medical or surgical history presented to the outpatient clinic department with incidental finding of left adrenal mass on ultrasonography. Physical examination was unremarkable. Computed tomography scan [Figure 1] was done which showed a non-enhancing hypodense mass of size 6 cm × 5 cm involving the left suprarenal region with left adrenal gland not separately visualised, suggesting an adrenal adenoma. Haematological and biochemical tests including free cortisol in a 24-h urine sample, 1-mg dexamethasone suppression testing, serum testing for basal cortisol and serum metanephrine levels were normal. Laparoscopic left adrenalectomy was planned for the patient because of the large size and possibility of pressure symptoms.

Figure 1

Computed tomography scan showing left adrenal mass

On the operating table, the patient was placed in the right lateral decubitus position, left side up at a 45–60° angle in the reverse Trendelenburg position with the left arm positioned as for a left lateral thoracotomy. Operating table was flexed 30° at the flank to increase the distance between the lower rib and the iliac crest. Three ports were placed. Gerota's fascia was exposed by mobilising the splenic flexure and lateral mobilisation of the spleen. Gerota's fascia was opened at the visualised junction between the kidney and adrenal. The adrenal gland along with the mass was dissected and mobilised. Adrenal vein and artery were ligated and cut. Adrenal mass of size 7.5 cm × 5 cm × 4 cm was removed in toto in endobag by dilating 10-mm right-hand working port. Drain was inserted in operative area. Specimen extracted [Figure 2] was sent for histopathological examination. Histopathology of the specimen showed no granuloma or dysplasia or parasite. Mature ganglion cells in background of neurofibroma-like spindle cells were seen suggesting of GN [Figure 3].

Figure 2

Extracted adrenal specimen

Figure 3

Ganglion cells in background of neurofibroma

Post-operatively, the patient was started on liquid diet on the same day and semisolid diet on next day. The patient's recovery was uneventful and was discharged on the second post-operative day. The patient has been asymptomatic for 6 months and engaged in his routine activities.

DISCUSSION

With the advances of abdominal imaging, AI has now become a common finding in clinical practice. Although majority of cases are benign and non-functioning, the presence of an AI is still a concern for patients and physicians alike because of the risk of transition to malignancy or hormonal hyperfunction.[12] The main challenge in the management of AI is the appropriate selection of cases for surgery to achieve a balance between the risk of excessively broad surgical indications and the observation of asymptomatic secreting or malignant lesions. GN is a rare form of AI and rarely reported in range of 0%–6% of all AIs in the literature.[5] GN is a benign, differentiated neurogenic tumour that arises mainly from primordial neural crest cells and consists of mature Schwann cells, ganglion cells and nerve fibre. GN may occur along the paravertebral sympathetic ganglia, from the neck to the pelvis. They are more common in the posterior retroperitoneum (40%) and rarely found in the adrenal gland. GNs are often hormonally silent adrenal tumours, but secretory activity has been reported.[6] When such tumours arise from the adrenal medulla, their assessment and management are similar to that of other adrenal tumours. Definitive diagnosis is made only on histological examination. GNs are often asymptomatic even if they are large, but adrenalectomy is treatment for GN, with prognosis being very good with surgical removal. They are usually not associated with genetic abnormalities. However, RET proto-oncogene has been reported in literature, to be associated with GN.[7]

Laparoscopic adrenalectomy has become the gold standard in most patients with adrenal tumours. Laparoscopic procedures are associated with less post-operative discomfort, shorter hospital stay, less post-operative disability and a lower rate of complications.[45] Several laparoscopic approaches for adrenalectomy have been proposed in the literature. After the first laparoscopic adrenalectomy with transperitoneal lateral approach proposed by Gagner in 1992, the transperitoneal anterior and retroperitoneal approaches have also been reported.[345] Worldwide, the lateral approach is mostly performed, followed by the retroperitoneal and then by the anterior approaches. Lateral transperitoneal position, as was used in present case, is currently the most preferred position by surgeons as it provides better access to anatomic landmark with advantage of excellent exposure of the operative field along with shorter operative time and fewer perioperative complications. However, concurrent procedures (e.g., cholecystectomy) or conversion to open laparotomy may require repositioning of the patient. Anterior transperitoneal position has been advantageous if concurrent procedures are planned and also conversion to open laparotomy (if required) can be easily performed. However, due to moderate visualisation and difficult dissection, it is the less preferred position. Retroperitoneal approach gives advantage of the absence of any intraperitoneal dissection, no bowel manipulation and less postoperative pain, and it is preferred in obese patients or after previous intraperitoneal surgery. However, unfamiliar anatomy, difficult conversion to open and unfeasibility of concurrent intra-abdominal procedures are major drawbacks of this approach. The final choice of approach for laparoscopic adrenalectomy depends on the surgeon's expertise and preference.[145]

CONCLUSION

An adrenal GN is a rare, hormonally silent benign tumour. A definitive diagnosis can only be made by histological examination. Adrenalectomy is treatment of choice for GN. Awareness of its clinical presentation and good pathological expertise is important adjuncts in the diagnosis. Laparoscopic adrenalectomy has become the gold standard in most patients with adrenal tumours. The final choice of approach for laparoscopic adrenalectomy depends on surgeon expertise.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.