(NON SOLUS
ELSEVIER
Journal of Pediatric urology
Laparoscopic adrenalectomy in children
Roberto Iglesias Lopes, Francisco Tibor Dénes*, Júlio Bissoli, Berenice Bilharino Mendonca, Miguel Srougi
Division of Urology, Hospital das Clínicas, University of São Paulo Medical School, Rua Dr. Enéas de Carvalho Aguiar, 455 - 7 andar, São Paulo, Brazil
Received 31 March 2011; accepted 18 July 2011 Available online 29 September 2011
KEYWORDS
Adrenal glands; Laparoscopy; Children; Adrenalectomy; Surgical procedures; Minimally invasive
Abstract Purpose: Reporting on the laparoscopic technique for adrenal disease in children and adolescents has been limited. We review here our experience with laparoscopic adrenal surgery in children.
Patients and methods: 19 laparoscopic unilateral adrenalectomies were performed in 10 girls and 7 boys (mean age 3.9 years) during 1998-2011. The clinical diagnosis before surgery was virilizing tumor (n = 8), pheochromocytoma (n = 3), nonfunctioning solid adrenal tumor (n = 3), mixed adrenocortical tumor (n = 2), cystic adrenal mass (n = 1). Unilateral adrenal lesions were 20-65 mm at the longest axis on computerized tomography (12 right side, 7 left side).
Results: The final clinicopathological diagnosis was cortical adenoma (n = 9), pheochromocy- toma (n = 3, bilateral in two), neuroblastoma (n = 1), ganglioneuroblastoma (n = 1), gang- lioneuroma (n = 1), adrenocortical carcinoma (n = 1), benign adrenal tissue (n = 1). Average operative time was 138.5 min (range 95-270). Blood transfusion was required in one case (5%). No conversion to open surgery was required and no deaths or postoperative complications occurred. Average hospital stay was 3.5 days (range 2-15). Average postoperative follow-up was 81 months (range 2-144). Two contralateral metachronic pheochromocytomas associated with von Hippel-Lindau syndrome occurred, treated with partial laparoscopic adrenalectomy (one without postoperative need of cortisone replacement therapy).
Conclusions: Laparoscopic adrenalectomy is a feasible procedure that produces good results. It can be used safely to treat suspected benign and malignant adrenal masses in children with minimal morbidity and short hospital stay.
@ 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Introduction
Laparoscopic adrenalectomy has been increasingly employed to treat adrenal tumors since first reported in 1992 [1,2]. Adrenal gland tumors, which are often small and pathologically benign, are suitable for a laparoscopic approach in most instances [3,4]. Well-known advantages of laparoscopy over open surgery include shorter recovery time with reduced hospital stay and better cosmetic results. Nevertheless, laparoscopic adrenalectomy in the pediatric age group is still underreported and few studies have addressed its safety and outcomes [5-13]. Concerns about the infiltrative nature of adrenal neuroblastomas, the most common adrenal malignant tumor in children, the theoretical risk of recurrence due to spillage in cases of adrenal carcinomas, along with the technical difficulty in operating on small children, may explain the limited experience with laparoscopic adrenalectomy in children [10,14]. Even though sporadic tumors comprise the majority of adrenal pathologies in children, familial syndromes such as von Hippel-Lindau, multiple endocrine neoplasia type 2, von Recklinghausen and Sturge-Weber are associated with an increased incidence of pheochromocy- tomas in the pediatric age group [15-19]. More recently, laparoscopic partial adrenalectomy has been adopted as the mainstay of surgical treatment, since these tumors are frequently bilateral and may recur, and an adrenal sparing approach is highly desirable to avoid the need for lifelong cortisone replacement therapy [20-22].
The aim of this study was to review our experience with laparoscopic (total and partial) adrenalectomy in children with regard to feasibility and outcome.
Patients and methods
We retrospectively reviewed 19 consecutive laparoscopic adrenalectomies performed in 17 children at our institution over a 12-year period. The medical records of all patients were reviewed and data collected regarding patient age and sex, clinical diagnosis, location and size of adrenal tumor, operating time, conversion to open surgery, need of blood transfusion, postoperative hospital stay, complica- tions, pathologic findings, and follow-up.
Thorough preoperative clinical investigation was carried out by pediatric endocrinologists in all patients. Comput- erized tomography (CT) was performed to determine the site, size, and extent of the tumors, as well as the presence of distant metastases. Biochemical and hormonal profile was assessed in functioning adrenal lesions. In addition, patients with functional adrenal medullary lesions and neuroblastomas underwent metaiodobenzylguanidine scans. Whenever pheochromocytoma was suspected, alpha-blockers (for blood pressure control) and beta- blockers (for heart rate control) were administered preoperatively and a trained anesthesiologist performed a careful evaluation of the patient. Anesthetic care of patients with pheochromocytoma included continuous intraoperative blood pressure and heart rate control with adequate hydration, as well as the titrated use of nitro- prusside and beta-blockers (along with surgical pause) as required.
All patients received their habitual diet until the day before surgery and did not undergo bowel preparation. The laparoscopic access in all cases was the lateral trans- peritoneal approach, which has been extensively described [4]. None of the patients had undergone previous abdom- inal surgery, except for two with previous contralateral laparoscopic adrenalectomies. Briefly, patients were submitted to general anesthesia followed by insertion of orogastric and urethral catheters which were removed after the procedure. During induction, a dose of broad spectrum cephalosporin was given. Patients were posi- tioned in a 45° oblique decubitus, elevating the desired side according to tumor location. In unilateral tumors, total adrenalectomy was performed (LA).
Pneumoperitoneum was achieved with a Veress needle introduced in the lower margin of the umbilicus and maintained with a pressure of 10-13 mmHg. The first disposable 10-mm retractile tip trocar (Endopath, Ethicon Endosurgery Inc.) was introduced in the umbilicus, serving as the access to the 30° laparoscope. Two or three 5/11-mm trocars were further inserted under direct vision.
On the right side, the liver is lifted and stabilized with a grasper, and the hepatic flexure mobilized medially, exposing the upper pole of the kidney, the adrenal and the vena cava. Dissection is initiated on the lateral border of the vena cava, in order to visualize and ligate the main adrenal vein, which is short and enters the vena cava laterally. Ligature is ensured with 5-10-mm polypropylene clips. Dissection of all aspects of the adrenal gland is per- formed with a normal or harmonic scalpel, carefully cauterizing and sectioning all small vessels, particularly in its upper and medial borders. Direct manipulation or mobilization of the adrenal gland with graspers and scissors is minimized in order to preserve its integrity and preclude hemodynamic instability, which may occur in patients with pheochromocytoma. After complete dissection, the adrenal gland is entrapped in a plastic bag and removed intact through an augmented port incision. The surgical field is inspected and, after ensuring adequate hemostasis, the ports are closed without drains.
On the left side, the colon is mobilized from splenic angle to pelvic rim, exposing the anterior renal fascia, which is incised over the renal hilum, with identification of the left renal vein. The main left adrenal vein, visualized at the superior margin of the renal vein, is carefully dissected, ligated and sectioned between hemostatic polypropylene clips. Further dissection of the left adrenal is then per- formed in the same fashion as described for the right side. After removal of the adrenal gland, hemostasis is revised, the left colon is replaced to its anatomical position without sutures, and the ports are closed without drains.
When contralateral metachronic adrenal lesions develop after a unilateral adrenalectomy, laparoscopic partial adrenalectomy (LPA) may be considered in benign lesions, if it is apparent from imaging studies that the location and size of the tumors are such that a significant proportion of the normal adrenal tissue can be preserved, in order to prevent the need for corticosteroid replacement. Careful inspection of the organ during dissection is necessary to identify both the tumoral limits and the extension of the normal adrenal tissue. Complete removal of the adrenal tumor with a 3-mm margin of normal tissue must be
| Table 1 | Demographic data and results. | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pt. No. | Age | Sex | Diagnosis | Tumor Size (mm.) | Side | Conversion | Transfusion | Discharge home (days) | Follow-up (months) | Recurrence or metachronic tumor | Treatment | |
| 1 | 1y4m | M | Cortical tumor | 50 | L | No | No | 15 | 148 | No | ||
| 2 | 2y6m | F | Cortical tumor | 52 | L | No | No | 2 | 119 | No | ||
| 3 | 1y3m | F | Cortical tumor | 50 | R | No | No | 2 | 130 | No | ||
| 4 | 9y6m | M | Cortical tumor | 45 | R | No | No | 2 | 117 | No | ||
| 5 | 2y6m | F | Carcinoma | 50 | L | No | No | 7 | 114 | No | ||
| 6 | 9m | F | Neuroblastoma | 45 | R | No | No | 2 | 113 | No | ||
| 7 | 2y6m | F | Cortical tumor | 38 | L | No | No | 2 | 89 | No | ||
| 8 | 2y6m | F | Cortical tumor | 45 | L | No | No | 2 | 87 | No | ||
| 9 | 2y1m | F | Cortical tumor | 40 | R | No | No | 2 | 72 | No | ||
| 10 | 5y4m | F | Ganglioneuroblastoma | 65 | R | No | Yes | 4 | 70 | No | ||
| 11 | 13y4m | M | Pheochromocytoma | 30 | R | No | No | 7 | 67 | No | ||
| 12 | 1y1m | M | Benign tumor | 25 | R | No | No | 2 | 65 | No | ||
| 13 | 2y | M | Cortical tumor | 32 | R | No | No | 2 | 59 | No | ||
| 14 | 8y8m | F | Pheochromocytoma | 55 | R | No | No | 5 | 50 | Yes | LPA | |
| 15 | 6y9m | M | Pheochromocytoma | 20 | R | No | No | 2 | 66 | Yes | LPA | |
| 16 | 4y2m | F | Ganglioneuroma | 40 | R | No | No | 2 | 9 | No | ||
| 17 | 1y8m | M | Cortical tumor | 45 | R | No | No | 2 | 2 | No | ||
| LPA = laparoscopic partial adrenalectomy. | ||||||||||||
achieved with the ultrasonic scalpel. Although the ligature and section of the main adrenal vein is not desirable when LPA is to be performed, in one of our two cases successful preservation of residual adrenal tissue was achieved after such section, due to a medially located tumor.
Postoperatively, cephalosporin was continued until the second postoperative day. In LPA with previous contralat- eral adrenalectomy, cortisone supplementation must be initiated postoperatively, and maintained according to need.
Results
Nineteen laparoscopic adrenalectomies were performed in 10 girls and 7 boys (mean age 3.9 years) between September 1998 and May 2011. None of the patients had undergone previous abdominal surgery, except for two with previous contralateral laparoscopic adrenalectomies. LA was performed in 17 unilateral cases, while LPA was per- formed in 2 cases due to metachronic tumor in the contralateral adrenal. Data are summarized in Table 1.
Adrenal tumor was on the right side in 10 patients, on the left side in 5 patients, and bilateral in 2 patients. Nonfunctioning solid adrenal tumor was identified as an abdominal mass in 1 patient and as an incidental finding in 2 patients. Respectively, a cystic adrenal mass was identified at antenatal ultrasonography at 35 weeks of gestation in the first patient, CT for the investigation of recurrent bronchopneumonia revealed a right adrenal lesion in the second patient, and follow-up abdominal ultrasonography for grade III vesicoureteral reflux managed clinically revealed a right adrenal tumor in the third patient. In the remaining 12 patients with unilateral tumors, clinical manifestations were hypertension in 3 patients and virili- zation in 9 patients (associated with Cushing symptoms in 2). Bilateral cases were familial pheochromocytomas asso- ciated with von Hippel-Lindau syndrome.
Preoperatively, clinical diagnosis was virilizing tumor (8 patients), nonfunctioning solid adrenal tumor (3 patients), pheochromocytoma (3 patients, bilateral in 2), mixed adrenocortical tumor (2 patients), cystic adrenal mass (1 patient). Unilateral adrenal lesions were 20-65 mm at the longest axis on CT (mean 42.4 mm).
The final pathological diagnosis was cortical adenoma (n = 9), pheochromocytoma (n = 3, bilateral in two), neuroblastoma (n = 1), ganglioneuroma (n = 1), ganglio- neuroblastoma (n = 1), adrenocortical carcinoma (n = 1), benign adrenal tissue (n = 1). Mean weight of the surgical specimens was 23 g (5-70 g). Average operative time was 138.5 min (range 95-270).
Blood transfusion was required intraoperatively in one girl (5%) who had a 6.5-cm ganglioneuroblastoma. The tumor was successfully treated by LA but dissection was difficult (Fig. 1a and b). There was no postoperative transfusion. No conversion to open surgery was required. Solid adrenal tumor was considered malignant in 1 case, a 21/2-year-old girl with a 5-cm tumor, in whom a tumoral thrombus in the adrenal vein was identified during surgery (Fig. 2a, b and c). No deaths or postoperative complications occurred. Average hospital stay was 3.5 days (range 2-15). In 1 case of mixed adrenocortical tumor, it was clinically difficult to manage
hypertension. Several drugs used preoperatively were progressively reduced after adrenalectomy and, as a result, this patient required hospitalization for 15 days (which increased the average hospital stay).
Average postoperative follow-up was 81 months (range 2-144). Two contralateral metachronic tumors occurred for pheochromocytomas associated with Von-Hippel Lindau syndrome (there are two cases and not just one). A girl aged 8 years and 8 months was submitted to right LA for a 5.5-cm lesion and after 24 months presented a 6-cm left metachronic pheochromocytoma, treated by LPA. Cortico- steroid replacement was needed in this case, with progressive dose reduction after 18 months. A boy aged 6 years and 9 months was submitted to a right LA for a 2-cm
a
b
1
a
L.kidney
Tumor
b Tumor
L.kidney
thrombus
c Removed L. adrenal vein with thrombus
dissected L. adrenal
tumor and after 53 months presented a 2.6-cm left meta- chronic pheochromocytoma, which was treated by a successful LPA. The main adrenal vein was ligated, but adequate perfusion of the significant amount of remnant left adrenal tissue was confirmed during surgery (Fig. 3a, b and c). In this case, cortisone replacement was inter- rupted after 3 days.
Discussion
Although laparoscopic adrenalectomy has been shown to have potential advantages over the open approach in
adults, reports are limited in the literature for the pediatric age group [5-13]. With the growing experience of laparo- scopic surgery in children, the trend is toward the increased use of LA in this age group [10]. Because of its small size and retroperitoneal location, the adrenal gland is suitable for laparoscopic resection. Our choice of the transperitoneal approach is based mainly on preference, associated with the small size of the patients. The retro- peritoneal approach is employed for LA and LPA with good results in the adult population [23,24] and also in children [25,26]. Our 5% transfusion rate, without postoperative adverse events, is comparable to that reported in the literature [5-10].
In this series, LA was performed for varied pathologies with excellent results and little morbidity. We treated only three neurogenic tumors, as most of our cases were cortical tumors and pheochromocytomas, referred by pediatric endocrinologists.
In 14 patients (2 with bilateral disease) the tumors were small and benign, and so easily removed. For malignant cases and larger tumors, the LA was more challenging. Adrenocortical carcinoma (n = 1), neuroblastoma (n = 1), and ganglioneuroblastoma (n = 1) were the pathological diagnoses for these cases.
Most benign adrenal tumors in this series were small functioning adenomas, which presented with virilization with or without hypertensive symptoms. After clinical investigation, LA was performed with excellent results. In all patients, clinical symptoms resolved after surgery. One patient had an antenatal diagnosis of an adrenal cystic mass at 35-week-gestation abdominal ultrasonography. After birth, oncologic staff indicated surgery that revealed benign adrenal tissue.
Pheochromocytomas are rare tumors in children and adolescents, who have a higher frequency of bilateral tumors than adults (20% vs 5-10%) [15,16]. Most pheo- chromocytomas are sporadic, but this tumor may be familial and inherited as an autosomal dominant trait. Familial pheochromocytomas are associated with multiple endocrine neoplasia type 2 and neuroectodermal syndromes such as von Recklinghausen’s disease, as well as von Hippel-Lindau and Sturge-Weber syndromes [15-19]. In our series, we had two cases of familial pheochromocy- tomas who presented contralateral metachronic lesions, which were treated with LPA, in order to avoid lifelong corticosteroid replacement therapy. Underused in the past few years, LPA is gaining more support as first-line therapy for small adrenal tumors [27-30]. LPA for metachronic contralateral tumors after LA in patients with familial pheochromocytomas is exceedingly rare, with few cases reported in children [20-22]. Both our patients are still under close surveillance because of the increased risk of recurrence. One patient did not need cortisone therapy and the other is currently in progressive dose reduction.
Adrenal gland is the most common site of involvement of tumors of ganglion cell origin [31,32]. These tumors include ganglioneuroma (benign), neuroblastoma (malignant) and ganglioneuroblastoma (intermediate). Neuroblastoma and ganglioneuroblastoma most often occur in children, whereas ganglioneuroma tends to occur in adolescents and young adults. Neuroblastoma, the most common adrenal neoplasm in childhood, is a malignant tumor that consists of
a
R. tumor
b
4
L. tumor
₪.5KHz
SCIC
30
C
L. tumor
+
Normal tissue
primitive neuroblasts and may arise within the sympathetic plexus or adrenal medulla. It occurs most commonly during the first 10 years of life, with approximately 80% found in children under the age of 5 years. Neuroblastoma tends to infiltrate and sometimes invade adjacent organs and vessels, and may suffer tumor necrosis and hemorrhage [31,32]. Around 70% of affected patients have disseminated metastatic disease at the time of diagnosis. In Japan, screening programs have produced better results, with neuroblastomas detected earlier than 1 year of age due to different prognostic factors such as aneuploid chromo- somes, no N-myc amplification and favorable Shimada histology [14]. These tumors are often put on expectant management since they might regress and disappear, surgery being indicated for cases with progression. LA might be employed in such a circumstance, with an acceptable morbidity [33-35]. We do not share the Japanese experi- ence with neuroblastoma, and since there was no size reduction of the tumor in our 9-month-old patient patient
adrenalectomy was indicated. Ganglioneuroblastoma is a transitional tumor of sympathetic cell origin that contains elements of both malignant neuroblastoma (primitive neuroblasts) and benign ganglioneuroma (mature ganglion cells). They are most often seen in children 2-4 years of age, who have a better prognosis than those with neuro- blastomas. Both patients in our series with adrenal tumors of ganglion cell origin are alive and without evidence of disease.
Although it is difficult to define what is a large tumor in children, due to stature variation according to age, in cases of relatively large tumors and imaging features suggestive of adrenal malignancy we avoid laparoscopic surgery due to increased risk of recurrence and mortality [36,37]. Among our cases, there was only one case in whom, despite imaging exams that showed a homogeneous, regular tumor without invasion of vessels or adjacent organs, suggesting adenoma, adrenocortical carcinoma was suspected intra- operatively due to findings of tumoral thrombus in the
adrenal vein during laparoscopic dissection. We managed to remove the left adrenal ‘en bloc’ with the involved adrenal vein, without tumor spillage. Pathological examination confirmed malignancy, but the patient is alive without evidence of disease after 9 years.
Our data confirm that in children with relatively small adrenal tumors without signs of local invasion and/or metastases, laparoscopic adrenalectomy is a safe and feasible procedure with good results, minimal morbidity and a short hospital stay. Partial adrenalectomy can also be performed safely in selected patients of this age group.
Disclosure statement
No competing financial interests exist.
References
[1] Gagner M, Lacroix A, Bolté E. Laparoscopic adrenalectomy in Cushing’s syndrome and pheochromocytoma. N Engl J Med 1992;327(14):1033.
[2] Higashihara E, Tanaka Y, Horie S, Aruga S, Nutahara K, Homma Y, et al. A case report of laparoscopic adrenalectomy. Nippon Hinyokika Gakkai Zasshi 1992;83(7):1130-3.
[3] Castilho LN, Mitre AI, Arap S. Laparoscopic adrenal surgery in a Brazilian center. J Endourol 2003;17(1):11-8.
[4] Terachi T, Matsuda T, Terai A, Ogawa O, Kakehi Y, Kawakita M, et al. Transperitoneal laparoscopic adrenalectomy: experi- ence of 100 patients. J Endourol 1997;11(5):361-5.
[5] Castilho LN, Castillo OA, Dénes FT, Mitre Al, Arap S. Laparo- scopic adrenal surgery in children. J Urol 2002; 168:221-4.
[6] Laje P, Mattei PA. Laparoscopic adrenalectomy for adrenal tumors in children: a case series. J Laparoendosc Adv Surg Tech A; 2009:S27-9. Suppl 1.
[7] Skarsgard ED, Albanese CT. The safety and efficacy of laparo- scopic adrenalectomy in children. Arch Surg 2005;140(9):905-9.
[8] Kadamba P, Habib Z, Rossi L. Experience with laparoscopic adrenalectomy in children. J Pediatr Surg 2004;39(5):764-7.
[9] Nerli RB, Reddy MN, Guntaka A, Patil S, Hiremath M. Laparo- scopic adrenalectomy for adrenal masses in children. J Pediatr Urol 2011;7(2):182-6.
[10] Romano P, Avolio L, Martucciello G, Steyaert H, Valla JS. Adrenal masses in children: the role of minimally invasive surgery. Surg Laparosc Endosc Percutan Tech 2007; 17(6):504-7.
[11] Al-Shanafey S, Habib Z. Feasibility and safety of laparoscopic adrenalectomy in children: special emphasis on neoplastic lesions. J Laparoendosc Adv Surg Tech A 2008; 18(2):306-9.
[12] Miller KA, Albanese C, Harrison M, Farmer D, Ostlie DJ, Gittes G, et al. Experience with laparoscopic adrenalectomy in pediatric patients. J Pediatr Surg 2002;37(7):979-82.
[13] Valla JS, Heloury Y, Mirallie E, Duverne C, Weill D, Delagausie P, et al. Laparoscopic adrenalectomy in children: experience of group d’etude en coeliochirurgie infantile in 16 cases. Pediatr Endosurg Innov Tech 201;5(3):267-275.
[14] Yamamoto H, Yoshida M, Sera Y. Laparoscopic surgery for neuroblastoma identified by mass screening. J Pediatr Surg 1996;31(3):385-8.
[15] Bissada NK, Safwat AS, Seyam RM, Al Sobhi S, Hanash KA, Jackson RJ, et al. Pheochromocytoma in childrens and adoles- cents: a clinical spectrum. J Pediatr Surg 2008;43:540-3.
[16] Safwat AS, Bissada NK, Seyam RM, Al Sobhi S, Hanash KA. The clinical spectrum of phaeochromocytoma: analysis of 115 patients. BJU Int 2008; 101:1561-4.
[17] Baghai M, Thompson GB, Young Jr WF, Grant CS, Michels VV, van Heerden JA. Pheochromocytomas and paragangliomas in von-Hippel Lindau disease. Arch Surg 2002;137:682-9.
[18] Bryant J, Farmer J, Kessler LJ, Townsend RR, Nathanson KL. Pheochromocytoma: the expanding genetic differential diag- nosis. J Natl Cancer Inst 2003;95(16):1196-204.
[19] Lonser RR, Glenn GM, Walther M, Chew EY, Libutti SK, Linehan WM, et al. von Hippel-Lindau disease. Lancet 2003; 361: 2059-67.
[20] Nambirajan T, Leeb K, Neumann HP, Graubner UB, Janetschek G. Laparoscopic adrenal surgery for recurrent tumors in patients with hereditary phaeochromocytoma. Eur Urol 2005;47(5):622-6.
[21] Nambirajan T, Bagheri F, Abdelmaksoud A, Leeb K, Neumann H, Graubner UB, et al. Laparoscopic partial adrenalectomy for recurrent pheochromocytoma in a boy with Von Hippel-Lindau disease. J Laparoendosc Adv Surg Tech A 2004; 14(4):234-5.
[22] Cheng SP, Saunders BD, Gauger PG, Doherty GM. Laparoscopic partial adrenalectomy for bilateral pheochromocytomas. Ann Surg Oncol 2008; 15(9):2506-8.
[23] Wang WJ, Shen ZJ, Zhu Y, Zhang RM, Shun FK, Shao Y, et al. Retroperitoneoscopic partial adrenalectomy for small tumors (<or = 1 cm): the Ruijin clinical experience in 88 patients. BJU Int 2010; 105(6):849-53.
[24] Walz MK, Peitgen K, Diesing D, Petersenn S, Janssen OE, Philipp T, et al. Partial vs total adrenalectomy by the posterior retroperitoneoscopic approach: early and long-term results of 325 consecutive procedures in primary adrenal neoplasias. World J Surg 2004;28(12):1323-9.
[25] Steyaert H, Juricic M, Hendrice C, Lembo MA, Al Mohaidly M, Guitard D, et al. Retroperitoneoscopic approach to the adrenal glands and retroperitoneal tumors in children: where do we stand? Eur J Pediatr Surg 2003;13(2):112-5.
[26] López PJ, Pierro A, Curry JI, Mushtaq I. Retroperitoneoscopic adrenalectomy: an early institutional experience. J Pediatr Urol 2007;3(2):96-9.
[27] Iihara M, Suzuki R, Kawamata A, Omi Y, Kodama H, Igari Y, et al. Adrenal-preserving laparoscopic adrenal surgery in selected patients with bilateral adrenal tumors. Surgery 2003; 134(6):1066-72.
[28] Diner EK, Franks ME, Behari A, Linehan WM, Walther MM. Partial adrenalectomy: the National Cancer Institute experi- ence. Urology 205;66(1):19-23.
[29] Liao CH, Chung SD, Lai MK, Yu HJ, Chueh SC. Laparoscopic simultaneous bilateral partial and total adrenalectomy: a longer follow-up. BJU Int 2009;104(9): 1269-73.
[30] Kaye DR, Storey BB, Pacak K, Pinto PA, Linehan WM, Bratslavsky G. Partial adrenalectomy: underused first line therapy for small adrenal tumors. J Urol 2010; 184(1):18-25.
[31] Lonergan GJ, Schwab CM, Suarez ES, Carlson CL. Neuroblas- toma, ganglioneuroblastoma and ganglioneuroma: radiologic- pathologic correlation. Radiographics 2002;22(4):911-34.
[32] Rha SE, Byun JY, Jung SE, Chun HJ, Lee HG, Lee JM. Neuro- genic tumors in the abdomen: tumor types and imaging characteristics. Radiographics 2003;23(1):29-43.
[33] Leclair MD, de Lagausie P, Becmeur F, Varlet F, Thomas C, Valla JS, et al. Laparoscopic resection of abdominal neuro- blastoma. Ann Surg Oncol 2008;15(1):117-24.
[34] De Lagausie P, Berrebi D, Michon J, Philippe-Chomette P, El Ghoneimi A, Garel C, et al. Laparoscopic adrenal surgery for neuroblastomas in children. J Urol 2003;170(3):932-5.
[35] Iwanaka T, Arai M, Ito M, Kawashima H, Yamamoto K, Hanada R, et al. Surgical treatment for abdominal neuroblastoma in the laparoscopic era. Surg Endosc 2001;15(7):751-4.
[36] Miller BS, Ammori JB, Gauger PG, Broome JT, Hammer GD, Doherty GM. Laparoscopic resection is inappropriate in patients with known or suspected adrenocortical carcinoma. World J Surg 2010;34(6):1380-5.
[37] Fassnacht M, Allolio B. What is the best approach to an apparently nonmetastatic adrenocortical carcinoma? Clin Endocrinol (Oxf.) 2010;73(5):561-5.