Single-port transumbilical laparoscopic excision of retroperitoneal schwannoma mimicking a nonfunctional endocrine tumor in the body of the pancreas: a case report

Pancreatic Nerve Sheath Tumors: a Single Institutional Series and Systematic Review of the Literature

INTRODUCTION

Improvement in imaging has resulted in frequent diagnosis of benign and premalignant pancreatic tumors. Pancreatic nerve sheath (PNS) tumors are one of the rarest pancreatic tumors. Literature on PNS is limited and their biology is poorly understood. Here, we report the largest series of PNS tumors to date and review the literature to evaluate the current data available on PNS tumors.

METHODS

An institutional database was used to identify patients who underwent resection for PNS tumors. Clinicopathological characteristics and outcomes of these patients were reported. Furthermore, a review of literature was performed.

RESULTS

From January 1994 through December 2016, seven patients underwent resection for PNS tumors. The median age was 57.7 years (IQR, 44.9-61.9) and the sex was approximately equally distributed (male = 4; 57.1%). Three (42.9%) patients were diagnosed incidentally and six (85.7%) were misdiagnosed as having other pancreatic tumors. The median tumor size was 2.1 (IQR 1.8-3.0) cm and six (85.7%) had no nodal disease. At a median follow-up of 15.5 (IQR 13.7-49.3) months, six patients were alive without evidence of disease and one patient was lost to follow-up. The literature review identified 49 studies reporting 54 patients with PNS tumors. Forty-six were misdiagnosed as having other pancreatic tumors. The median tumor size was 3.6 (range 1-20) cm, nodal disease was present in six patients (22.2%), and no patient had distant metastatic disease. At the time of last follow-up, all patients were free of disease.

CONCLUSION

This is the largest single institution series on PNS tumors reported to date. These tumors are rare and are often misdiagnosed, given their radiological characteristics. PNS tumors have a benign course of disease and surgical resection results in favorable long-term outcomes.

Pancreatic schwannoma, an extremely rare and challenging entity: Report of two cases and review of literature

Pancreatic schwannoma is a rare benign tumor, for which the preoperative and intraoperative definitive diagnosis is quite challenging. We present the clinical, radiological and pathologic features of two primary pancreatic schwannomas identified in our pathology database over a period of 30 years at our tertiary care hospital. To better understand the clinico-pathological and radiological features of this entity, we provide a comprehensive review of 73 cases described in the English literature, along with our two cases. This review will especially focus on preoperative and intraoperative diagnosis to assess their accuracy for pancreatic schwannoma. The three most common preoperative diagnoses based on imaging for pancreatic schwannomas were cystic neoplasm (56%), pancreatic neuroendocrine tumor (29%) and mucinous cystic neoplasm (26%). Imaging could not definitely diagnose pancreatic schwannoma in any of the reported cases. To obtain a definite diagnosis before surgery, 25 cases underwent imaging-guided fine-needle aspiration (FNA)/biopsy, of which 60% were correctly reported as benign with definite diagnosis of pancreatic schwannoma in 48%. A higher diagnostic accuracy was observed in biopsies (71%) than FNA (37%). In addition, an intraoperative frozen section was carried out in 15 cases, and 47% were correctly diagnosed. Despite relatively low accuracy, preoperative histological assessment can be helpful in surgical managment. A core tissue specimen is recommended to improve the diagnostic accuracy in this setting.

Laparoscopic Excision of Retroperitoneal Schwannoma

Schwannomas are tumours that arise from the myelin sheath of the nerves. A very unusual location for schwannoma is the retro peritoneal areas (less than 2%). We present herewith a patient who had a 4x5cm Schwannoma arising from the nerve root of L2 on the right side, which presented as a lump in the psoas major muscle. This was treated by total laparoscopic excision after splitting open the psoas major. In the published english medical literature we could find only 16 cases of laparoscopic resection of retroperitoneal schwannoma and we believe ours to be the first case that was done through a psoas muscle split technique. Technical and histopathological details are discussed elaborately in this article.

Single-incision laparoscopic excision of pancreatic tumor in children

PURPOSE

Single-incision laparoscopic surgery (SILS) as a surgical approach in treatment of pancreatic disease has recently been reported in adults. However, its application in pancreatic surgery in children is limited. In this article, we report our preliminary experience of SILS in children with pancreatic disease.

METHODS

Three children with pancreatic tumor underwent single-incision laparoscopic partial pancreatectomy between July 2011 and August 2013. Two of three children were girls, and one was a boy. The ages ranged from 2 to 10 months, with an average age of 6.7 months.

RESULTS

All operations were successfully performed. There was no conversion to the conventional multi-incision surgery. The mean operation time of the 3 cases was 153.3 minutes (range 120-200 minutes). The postoperative hospital stay was 7 days. The drainage tubes were kept for 3 to 4 days after surgery. There was no pancreatic juice leak in this case series. All patients were followed up and there was no recurrence.

CONCLUSIONS

Single-incision laparoscopic partial pancreatectomy for children with pancreatic tumor is feasible.