Pancreatic schwannoma: report of a case

Successful treatment of pancreatic schwannoma by enucleation: A case report

RATIONALE

Pancreatic schwannomas are extremely rare and are difficult to diagnose preoperatively. Over the past 50 years, only 96 cases of pancreatic schwannoma have been reported in English literature. Herein, we report a case of pancreatic schwannoma treated with enucleation.

PATIENT CONCERNS

A 66-year-old woman visited a local hospital due to ventosities. Ultrasonography and computed tomography revealed a pancreatic mass. She visited our hospital for further diagnosis and treatment.

DIAGNOSIS AND INTERVENTIONS

Magnetic resonance imaging revealed a tumor in the pancreatic body, and a solid pseudopapillary tumor was considered preoperatively. During the surgery, a pancreatic mass was found growing in the pancreatic body and tail. A successful tumor enucleation was performed. The mass was 7 × 6 × 3 cm in size with a thin capsule. Pathological examination revealed that the tumor was mainly composed of spindle-shaped cells with a palisading arrangement and no atypia. Both hypercellular and hypocellular areas were visible. Immunohistochemical staining showed that protein S-100 was strongly positive. The tumor was diagnosed as a benign schwannoma originating from the pancreatic body and tail.

OUTCOMES

Postoperatively, the patient showed good recovery. During the 24-month follow-up period, the patient remained well and free of complications.

LESSONS

Pancreatic schwannomas are extremely rare and difficult to diagnose using imaging examinations. Enucleation is a safe and efficacious treatment for exophytic pancreatic schwannomas.

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.

Pancreatic schwannoma mimicking pancreatic cystadenoma: A case report and literature review of the imaging features

INTRODUCTION

Schwannomas, also known as neurilemmoma, are benign neoplasms that originating from Schwann cells in peripheral nerve sheaths. The head, neck, and extremities are the most common sites; however, pancreatic schwannomas are rare neoplasms. Accurate preoperative diagnosis of these tumors is very tough because of pancreatic schwannomas usually mimicking other cystic tumors. Here we present a case of pancreatic schwannoma misdiagnosed as pancreatic cystadenoma.

PATIENT CONCERNS

We presented a rare case of a 55-year-old female admitted to our hospital for abdominal distension. The physical examination and results of laboratory testing reveal no abnormalities.

DIAGNOSIS

A computed tomography (CT) scan detected a hypodense 2.4 cm × 2.6 cm mass with a clear margin at the neck of the pancreas. Pancreatic cystadenoma was strongly suspected.

INTERVENTIONS

The patient underwent robotic distal pancreatectomy with splenectomy. The gross specimen showed a pale and solid mass with a capsule.

OUTCOMES

Histological examination of the surgical specimen demonstrated a pancreatic schwannoma. Immunohistochemistry results were as follows: S-100 (+), CD117 (-), SMA (-), and Desmin (-). She was discharged on postoperative day 6 and no recurrence of the tumor happened during the 12-month follow-up.

CONCLUSION

Precise preoperative diagnosis of pancreatic schwannomas is very difficult despite the application of multiple imaging modalities. Surgery is the most effective treatment for this rare disease and the final diagnosis usually relies on pathology. Following complete tumor removal, patients with pancreatic schwannomas generally have a good prognosis.

Successful treatment of a pancreatic schwannoma by spleen-preserving distal pancreatectomy

Schwannomas are neurogenic tumors that arise from the neural sheaths of peripheral nerves. These tumors can be located in any area of the human body; the most common locations are the head, neck, trunk and extremities. Pancreatic schwannomas are very rare. Over the past 40 years, only 67 cases of pancreatic schwannomas have been reported in the English literature. Here we present a case of pancreatic schwannoma in a 62-year-old male. The tumor was revealed by ultrasound and computed tomography in the neck and body of the pancreas. An accurate diagnosis was difficult to obtain preoperatively. The patient consented to the performance of a laparotomy, and the mass was found in the neck and body of the pancreas and successfully treated using a spleen-preserving distal pancreatectomy with splenic artery and vein preservation. The procedure has only been reported in one other case of pancreatic schwannoma; here we present the second reported case. Macroscopically, the tumor was well circumscribed, gray-white in color and 3.3 cm × 2.8 cm in size. Microscopically, the tumor cells were spindle-shaped and had a palisading arrangement with no atypia, which are results compatible with a benign tumor. Both hypercellular and hypocellular areas were visible. Immunohistochemically, the tumor cells were strongly positive for S-100 protein. The tumor was definitively diagnosed as a schwannoma of the pancreatic neck and body. The patient was followed for 72 mo and has been doing well without any complications.

Pancreatic schwannoma: a case report and an updated 40-year review of the literature yielding 68 cases

BACKGROUND

Pancreatic schwannoma is a rare tumor. Preoperative diagnosis of pancreatic schwannoma is challenging due to its tendency to mimic other lesions of the pancreas. We describe a case of pancreatic schwannoma and present a review of the cases currently reported in the English literature to identify characteristics of pancreatic schwannoma on imaging.

CASE PRESENTATION

A 53-year-old male presented with a history of intermittent periumbilical abdominal pain and lower back pain for 1 week. Based on ultrasound (US) and computed tomography (CT) findings, we made a preoperative diagnosis of solid pseudopapillary tumor and performed a standard pancreaticoduodenectomy. Pathological examination showed that the tumor was composed of spindle cells with a palisading arrangement, and immunohistochemistry revealed strong positive staining for S-100 protein, which was consistent with a diagnosis of pancreatic schwannoma. At the 8-month follow-up visit, the patient was doing well without recurrent disease, and his abdominal pain had resolved.

CONCLUSIONS

Although pancreatic schwannoma is rare, it should be included in the list of differential diagnoses of pancreatic masses, both solid and cystic. A tumor size larger than 6.90 cm, vascular encasement, or visceral invasion should elicit suspicion of malignant transformation.

Successful treatment of a pancreatic schwannoma by spleen-preserving distal pancreatectomy

Schwannomas are neurogenic tumors that arise from the neural sheaths of peripheral nerves. These tumors can be located in any area of the human body; the most common locations are the head, neck, trunk and extremities. Pancreatic schwannomas are very rare. Over the past 40 years, only 67 cases of pancreatic schwannomas have been reported in the English literature. Here we present a case of pancreatic schwannoma in a 62-year-old male. The tumor was revealed by ultrasound and computed tomography in the neck and body of the pancreas. An accurate diagnosis was difficult to obtain preoperatively. The patient consented to the performance of a laparotomy, and the mass was found in the neck and body of the pancreas and successfully treated using a spleen-preserving distal pancreatectomy with splenic artery and vein preservation. The procedure has only been reported in one other case of pancreatic schwannoma; here we present the second reported case. Macroscopically, the tumor was well circumscribed, gray-white in color and 3.3 cm × 2.8 cm in size. Microscopically, the tumor cells were spindle-shaped and had a palisading arrangement with no atypia, which are results compatible with a benign tumor. Both hypercellular and hypocellular areas were visible. Immunohistochemically, the tumor cells were strongly positive for S-100 protein. The tumor was definitively diagnosed as a schwannoma of the pancreatic neck and body. The patient was followed for 72 mo and has been doing well without any complications.

Central pancreatectomy for pancreatic schwannoma: A case report and literature review

Schwannomas are mesenchymal tumors originating from Schwann cells in peripheral nerve sheaths. Although the tumor can be located in any part of the human body, the most common locations are the head, neck, trunk and extremities. Pancreatic schwannomas are rare. To our knowledge, only 64 cases of pancreatic schwannoma have been reported in the English literature over the past 40 years. In this paper, we present a pancreatic schwannoma in a 59-year-old female. Ultrasound, computed tomography and magnetic resonance imaging revealed the tumor located in the pancreatic body; however, accurate diagnosis was hard to obtain preoperatively and a pancreatic cystadenoma was preliminarily considered. During laparotomy, the mass was found in the body of the pancreas. An enlarged gallbladder with multiple stones was also observed. We performed central pancreatectomy, end-to-side pancreaticojejunostomy and cholecystectomy. Notably, central pancreatectomy has been reported in only one case prior to this report. The gross specimen showed a mass with a thin capsule, 1.6 cm × 1.1 cm × 1.1 cm in size. Microscopic examination showed that the tumor was mainly composed of spindle-shaped cells with palisading arrangement and no atypia, which is consistent with a benign tumor. Both hypercellular and hypocellular areas were visible. Immunohistochemical staining revealed strongly positive results for protein S-100. Finally, the tumor was diagnosed as a schwannoma of the pancreatic body. Postoperatively, the patient recovered well and left the hospital 6 d later. During the 53-mo follow-up period, the patient remained well and free of complications.

Pancreatic schwannoma: A case report and review of the literature

Schwannoma or neurilemmoma is a well-defined, benign tumor, which arises from neural crest cells and surrounds the nerve sheath. It is rare neoplasm that is typically found in the extremities, such as the thorax, head, neck, pelvis and rectum. Schwannoma localized to the pancreas is particularly rare and only a limited number of cases have been reported in the literature to date. The present study reports the case of a 30-year-old male with pancreatic schwannoma presenting with weight loss and abdominal pain. Pancreatic schwannoma was diagnosed using magnetic resonance imaging and ultrasonography-guided biopsy, which was followed by a duodenopancreatectomy. Although pancreatic schwannomas are rare, they must be considered during the differential diagnoses of cystic pancreatic masses.

Pancreatic tail schwannoma in a 44-year-old male: a case report and literature review

Pancreatic schwannomas are exceedingly uncommon neoplasms. According to a recent study in 2012, less than 50 cases of pancreatic schwannoma have been described in the English literature over the past thirty years. The vast majority of pancreatic schwannomas take place in the head and body of pancreas, respectively. Herein, we report the case of pancreatic tail ancient schwannoma in a 44-year-old man who presented with a 4-month history of epigastric pain. On physical examination, epigastric region was moderately tender to palpation without evidence of a palpable mass. All laboratory tests were normal. Contrast-enhanced computed tomography (CT) scan showed a 9.2 × 9.5 × 11.5 cm, huge, and well-defined left suprarenal mass arising either from adrenal gland, pancreas, or retroperitoneum. The mass demonstrated mild heterogeneous enhancement with central cystic/necrotic area. No evidence of distant metastasis was identified. At laparoscopy, the mass was noticed to originate from pancreatic tail. Patient underwent surgical resection of pancreatic tail. Microscopic and immunohistochemical examination of the pancreatic tail specimen showed ancient schwannoma. Patient received no adjuvant therapy. At a postoperative 6-month followup, patient was completely asymptomatic and CT scan imaging showed no evidence of tumor recurrence. Moreover, a literature review on pancreatic schwannomas is presented.

Pancreatic schwannoma: Case report and an updated 30-year review of the literature yielding 47 cases

Pancreatic schwannomas are rare neoplasms. Authors briefly describe a 64-year-old female patient with cystic pancreatic schwannoma mimicking other cystic tumors and review the literature. Databases for PubMed were searched for English-language articles from 1980 to 2010 using a list of keywords, as well as references from review articles. Only 41 articles, including 47 cases, have been reported in the English literature. The mean age was 55.7 years (range 20-87 years), with 45% of patients being male. Mean tumor size was 6.2 cm (range 1-20 cm). Tumor location was the head (40%), head and body (6%), body (21%), body and tail (15%), tail (4%), and uncinate process (13%). Thirty-four percent of patients exhibited solid tumors and 60% of patients exhibited cystic tumors. Treatment included pancreaticoduodenectomy (32%), distal pancreatectomy (21%), enucleation (15%), unresectable (4%), refused operation (2%) and the detail of resection was not specified in 26% of patients. No patients died of disease with a mean follow-up of 15.7 mo (range 3-65 mo), although 5 (11%) patients had a malignancy. The tumor size was significantly related to malignant tumor (13.8 ± 6.2 cm for malignancy vs 5.5 ± 4.4 cm for benign, P = 0.001) and cystic formation (7.9 ± 5.9 cm for cystic tumor vs 3.9 ± 2.4 cm for solid tumor, P = 0.005). The preoperative diagnosis of pancreatic schwannoma remains difficult. Cystic pancreatic schwannomas should be considered in the differential diagnosis of cystic neoplasms and pseudocysts. In our case, intraoperative frozen section confirmed the diagnosis of a schwannoma. Simple enucleation may be adequate, if this is possible.

Microcystic/reticular schwannoma of the pancreas: a potential diagnostic pitfall

Schwannomas occurring in the pancreatic head are rare benign non-recurring mesenchymal neoplasms and are reported to show classic morphologic features. Herein we report a case of a 62 year old male presenting with a 5 cm mass in the pancreatic head encasing the portal vein and the truncus coeliacus. Preoperative fine needle aspiration revealed malignant tumour cells consistent with a moderately differentiated adenocarcinoma. A Whipple surgery was performed after palliative chemotherapy. Histological evaluation revealed a multinodular unencapsulated tumour with focal infiltration into pancreas parenchyma and a striking microcystic/reticular growth pattern. Anastomosing and intersecting strands of spindle cells with eosinophilic cytoplasm set in a myxoid partly collagenous stroma were observed. The tumour cell nuclei were round oval and tapered and showed inconspicuous small nucleoli. Degenerative nuclear atypia was seen. Mitotic activity was sparse (1/50 HPF). Pleomorphism or necrosis was absent. The tumour cells showed strong nuclear and cytoplasmic positivity for S-100 protein, and focal positivity for glial fibrillary acidic protein. The diagnosis of a microcystic/reticular schwannoma was made. The awareness of and, to some extent, the knowledge about this rare tumour are needed to achieve the correct diagnosis and to avoid confusion, especially with malignant pancreatic neoplasms.

Pancreatic schwannoma: literature review

Pancreatic schwannoma is a rare neoplasm. Accurate preoperative diagnosis remains difficult, but computed tomography (CT) scanning and magnetic resonance imaging (MRI) help to establish the diagnosis, and definitive diagnosis requires immunohistochemical examination. Cystic pancreatic schwannomas should be considered in the differential diagnosis of cystic neoplasms and pseudocysts. Simple enucleation may be adequate for pancreatic schwannoma. In this report, we examine a case of benign pancreatic schwannoma in a 56-year-old woman. She was being evaluated for an ovarian teratoma, and an 8-cm cystic mass was incidentally found in the head of the pancreas. She underwent a pylorus preserving Whipple procedure with bilateral oopherectomy. Only 37 cases have been reported in the English literature. We present a thorough review with an emphasis on the clinical presentation, diagnostic modalities, and treatment options in the management of this rare clinical entity.

Solitary fibrous tumor of the pancreas

A 67-year-old woman was found to have an incidental pancreatic mass on computed tomographic examination of her abdomen in the course of investigation of hematuria. The radiologic features were of a hypervascular mass in the uncinate process of the head of the pancreas, and a preoperative diagnosis of a neuroendocrine tumor was favored. A Whipple procedure was performed. The uncinate process contained a 2.6-cm well-circumscribed mass. Histologic evaluation showed a lesion composed of alternating hypercellular areas made up of spindle-shaped cells and hypocellular areas with hyalinized, keloidal-like fibrous tissue. Occasional dilated vascular channels and entrapped pancreatic tissue were present within the lesion. Immunohistochemistry showed the lesion to be CD34, CD99, and bcl-2 positive. No evidence of atypia was noted, and the overall impression was of a benign solitary fibrous tumor of the pancreas. This is an unusual primary spindle cell neoplasm of the pancreas and should be considered in the differential diagnosis of all spindle cell lesions that occur in the pancreas.