Pancreatic schwannoma: A rare case and a brief literature review

Successfully enucleation of a rare pancreatic schwannoma: A case report

INTRODUCTION AND IMPORTANCE

Pancreatic schwannoma (PS) is an extremely rare benign tumor also known as neurilemoma or neuroma. The majority of PS develop cystic lesions, and its preoperative diagnosis is challenging due to its tendency to mimic other lesions of the pancreas. Herein, we reported a case of body PS incidentally discovered in an 81-year-old male, which was successfully treated through enucleation.

CASE PRESENTATION

We report the case of a 81-year-old man. Who presented with a well-defined polycystic-tumor of about 2cm at the pancreatic body, overdrawn by a computed tomography scan, incidentally discovered. The patient underwent a laparotomy, and we performed an enucleation of the tumor successfully. Histopathological examination revealed spindle-shaped cells. Immunohistochemically studies showed S100-protein expression, confirmed a body pancreatic schwannoma. The postoperative course was uneventful.

CLINICAL DISCUSSION

Schwannomas are rare mesenchymal-tumors, with PS accounting for only 1 % of cases. They are often difficult to diagnose as they mimic other pancreatic tumors. Imaging techniques like CT, MRI, and EUS-FNA aid in detection, but definitive diagnosis requires histological and immunohistochemical analysis. Treatment is typically enucleation for benign tumors, but larger or malignant tumors may need more extensive resections. Due to diagnostic challenges, aggressive surgeries are common. Prognosis is generally favorable, but regular follow-ups are recommended to monitor for recurrence.

CONCLUSION

Although pancreatic schwannoma is rare, it should be included in the list of differential diagnoses of pancreatic masses, both solid and cystic. Both enucleation and radical surgical resections have revealed great therapeutic efficiency with a well prognosis without recurrences.

Clinical benefits of central pancreatectomy for a patient with pancreatic schwannoma and diabetes

Schwannomas are tumors that originate from the glial cells of the nervous system and can occur on myelinated nerve fibers throughout the body, especially in the craniofacial region. However, pancreatic schwannomas are extremely rare. We report a case of a pancreatic schwannoma that was difficult to differentiate from other pancreatic tumors preoperatively. A 44-year-old female patient was found to have a pancreatic mass on Computed Tomography imaging and the preoperative diagnosis was a pancreatic solid pseudopapillary neoplasm. Meanwhile, the patient had type 2 diabetes and the blood glucose was controlled at 8-15mmol/L by taking oral antidiabetic drugs. During exploratory laparotomy, an 8 cm × 7 cm × 4 cm mass was discovered in the middle part of the pancreas. Considering the preoperative diabetes, the patient underwent a central pancreatectomy (CP) and Roux-en-Y pancreaticojejunostomy. Postoperative histopathological examination confirmed the diagnosis of a pancreatic epitheloid schwannoma. After surgery, the patient developed Grade B pancreatic fistula, which disappeared after treatment. At the same time, the patient's blood glucose remained basically stable by insulin therapy, which was adjusted to oral antidiabetic medications in about 40 days after surgery. At a 32-month follow-up after discharge, no tumor recurrence was observed, and the patient's blood glucose was controlled below 11.1mmol/L with only oral antidiabetic drugs. The radiological diagnosis of pancreatic schwannomas lacks specific features, and diagnosis primarily relies on histopathological examination and immunohistochemical testing. Although pancreatic schwannomas are extremely rare, they must be differentiated from other solid or cystic pancreatic lesions. For patients with pancreatic schwannoma and diabetes, CP may represent a favorable surgical option.

Pancreatic schwannoma: a rare differential diagnosis for a pancreatic mass

Pancreatic schwannomas are rare benign tumors with low malignant potential and are often difficult to diagnose due to their non-specific presenting symptoms and overlapping radiological imaging characteristics. Cross-sectional imaging plays an important role in the initial diagnosis and in delineating the extent of the lesion. However, biopsy and histopathological examination remains the gold-standard for a definite diagnosis. The management of pancreatic schwannomas includes surgical resection often yielding excellent clinical outcomes with low recurrence rates. We present a case of a 33-year-old female patient with a history of a recurrent vague upper abdominal pain where CT of the upper abdomen showed a hypodense pancreatic mass. Robotic subtotal pancreatectomy was done with histopathology showing spindled Schwann cells indicative of a pancreatic schwannoma.

CT of pancreatic schwannoma

Schwannomas are a type of nerve sheath tumor formed by Schwann cells. They typically occur in the head and neck area, the trunk, and flexor surfaces of the upper and lower extremities. Schwannomas are often benign, and pancreatic schwannomas are extremely uncommon. Given the rarity of these tumors and their clinical similarity to other pancreatic lesions, however, pancreatic schwannomas are challenging to diagnose preoperatively. In this article, we report the case of a 69-year-old female who was diagnosed with a pancreatic schwannoma. We focus on optimizing diagnosis and management through the application of radiological imaging modalities, specifically computed tomography scans with cinematic rendering.

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.

Schwannoma mimicking pancreatic carcinoma: A case report

BACKGROUND

Schwannoma of the pancreas is extremely rare. We report a case of pancreatic schwannoma that was difficult to distinguish from pancreatic carcinoma before surgery.

CASE SUMMARY

A 66-year-old male underwent a right-lobe hepatectomy for hepatocellular carcinoma. Post-surgical computed tomography showed a 10 mm long solid mass with ischemia, with no expansion into the main pancreatic duct. Upon magnetic resonance cholangiopancreatography, the tumor had high signal intensity in diffusion weighted images, consistent with pancreatic carcinoma. Endoscopic ultrasound (EUS) was performed to obtain more information about the tumor, and showed a 14 mm solid and hypoechoic mass in the pancreatic body. Contrast enhanced EUS revealed that the tumor showed a hyperechoic mass in the early phase, and the contrasting effect continuation was very short; findings also consistent with pancreatic carcinoma. Thus, we preoperatively diagnosed his condition as a pancreatic carcinoma and performed distal pancreatectomy with splenectomy. Microscopic examination showed that the tumor was in fact a benign schwannoma. Histology showed a proliferation of spindle-shaped cell in a vague fascicular and haphazard pattern, with palisading arrangement.

CONCLUSION

Schwannoma of the pancreas is very rare, however, clinicians should consider schwannoma as the differential diagnosis for pancreatic tumors.

Peripancreatic schwannoma: A case report

Introduction

Schwannomas are a benign tumor of peripheral nerve sheath origin. Although most commonly arising in the extremities, head, and neck there have been rare cases of schwannomas presenting within or adjacent to the pancreas reported in the literature.

Presentation of case

We present an asymptomatic and otherwise healthy 57-year-old male with an incidental peripancreatic mass measuring 3.5 × 3.7 cm found on abdominal computed tomography (CT). The patient underwent complete enucleation of the mass at our hospital. Pathological analysis of the excised specimen showed spindle shaped cells. Immunohistochemical staining was positive for S100 protein expression, confirming the definitive diagnosis of peripancreatic schwannoma. The patient's postoperative course was uneventful.

Discussion

Schwannoma is a commonly benign, encapsulated, and slowly growing tumor arising from myelin producing cells of peripheral nerves. A schwannoma presenting within or adjacent to solid abdominal viscera, such as the pancreas, may be challenging to diagnose preoperatively as it may mimic other lesions. Radiological appearance of schwannoma may be nonspecific and definitive diagnosis is reliant upon pathological analysis. The use of endoscopic ultrasound (EUS) with fine needle aspiration (FNA) may assist the clinician in preoperative diagnosis, however these interventions are not widely available. Accurate preoperative diagnosis of a peripancreatic schwannoma is of high importance as it may preclude unnecessary pancreatectomy or radical resection.

Conclusion

Although rare, schwannoma should be part of the differential diagnosis of a cystic or solid appearing mass within or surrounding the pancreas. Total resection carries an excellent prognosis with little to no documented recurrence.

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Peripancreatic schwannoma is rare, but should be considered in the differential diagnosis of an incidentally found mass

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Histopathological features of schwannoma

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Radiological features of schwannoma

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Enucleation of peripancreatic schwannoma carries excellent prognosis

Successful Enucleation of a Large Pancreatic Head Schwannoma

A presumed benign cystic tumor in the pancreatic head had been pointed out to a 78-year-old man 4 years ago. In addition to no communication between the tumor and the main pancreatic duct, magnetic resonance imaging showed that the cystic fluid was serous. Gradual tumor enlargement from 2.1 to 4.0 cm urged us to resect the tumor. In order to safely enucleate the tumor, we preoperatively placed a pancreatic duct stent and covered the pancreatic parenchyma with a polyglycolic acid sheet, fibrin glue, and thrombin after tumor enucleation. The patient postoperatively developed grade B pancreatic fistula but recovered with antibiotics therapy. Postoperative computed tomography showed successful preservation of the main pancreatic duct. Pathological study showed a well-defined tumor mainly composed of loosely textured and S-100-positive spindle cells with abundant and hyalinized blood vessels in the cystic walls with palisading spindle cells, leading to the diagnosis of Antoni B schwannoma. The patient was discharged on the 11th day after operation. Both pancreatic duct stunting and covering the exposed pancreatic parenchyma with a polyglycolic acid sheet, fibrin glue, and thrombin are feasible measures to enucleate large benign tumors in the pancreatic head.

MR imaging features of pancreatic schwannoma: a Chinese case series and a systematic review of 25 cases

BACKGROUND

There is a paucity of existing literature centering on the magnetic resonance (MR) imaging features of pancreatic schwannomas, due to the neoplasm's nonspecific presentation and its rarity. We aimed to identify the characteristic imaging features of pancreatic schwannoma.

METHODS

This retrospective search was conducted for histologically confirmed pancreatic schwannoma in multi-institutional database of pathology. Abdominal magnetic resonance imaging (MRI) was performed before histologic examination and their MR imaging studies were independently reviewed. The search yielded six adults (mean age, 46 years) with a definitive histologic postoperative diagnosis of single pancreatic schwannoma each. Additionally, a comprehensive English and Chinese literature review for pancreatic schwannoma and reported MR-imaging findings since 1961 was also conducted. MR imaging features of those cases in the literature were analyzed, summarized and compared with our case series.

RESULTS

This rare entity appeared to be a well-circumscribed, exophytic, oval or round pancreatic mass with a mean greatest diameter of 3.7 cm. Five schwannomas were located in the pancreatic head-neck and one in the pancreatic tail. On MRI, all cases appeared hypointense on T1-weighted images, inhomogeneous hyperintense on T2-weighted images, and hyperintense on diffusion-weighted images. The mean apparent diffusion coefficient (ADC) values of pancreatic schwannoma were 1.11 ± 0.29 × 10- 3 mm2/s and significantly lower than the surrounding pancreas. The lesion-to-pancreas signal intensity ratio (SIR) at unenhanced T1-weighted images was 0.53 ± 0.07. On dynamic contrast-enhanced MRI, most of the lesions (67%, 4/6) showed homogeneously iso- or hypointense on arterial and portal venous phases, and hyperenhancement on delayed phase compared with the surrounding pancreas. In our analysis of the time intensity curves, all cases exhibited a gradual enhancement pattern.

CONCLUSIONS

A well-circumscribed mass displaying inhomogeneous hyperintensity on T2, marked hypointensity on T1, hyperintensity on DWI, and with early slight enhancement at arterial phase and progressive enhancement at portal venous and delayed phase, may suggest the diagnosis of pancreatic schwannoma.

Imaging Features of Neurofibromatosis Type 1 in the Abdomen and Pelvis

OBJECTIVE. Loss of the neurofibromatosis type 1 (NF1) tumor suppressor protein causes uninhibited activation of the RAS oncogene, which leads to tumorigenesis in patients with NF1. This case-based review discusses imaging manifestations of NF1 in the abdomen and pelvis, highlighting key genetic associations and management to elucidate features different from the general population. CONCLUSION. The spectrum of pathologic findings includes gastrointestinal tumors such as gastrointestinal stromal tumors, genitourinary lesions including urogenital neurofibromas, vascular entities such as renal artery stenosis, and less common associations like lymphoma.

A rare tumour of pancreas-Case report

INTRODUCTION

Pancreatic schwannomas are very rare neoplasm arising from Schwann cells that present in the nerve sheath. Schwannoma usually occur in the extremities but can also be found in the trunk, head and neck, retroperitoneum, mediastinum, pelvis and rectum.

PRESENTATION OF CASE

We briefly describe a 30-year-old female patient with upper abdominal pain and on examination by ultrasound and Computed tomography of abdomen revealed a solid tumor arising from body of the pancreas. A laparoscopic splenic vessel preserving distal pancreatectomy (kimura) was performed.

DISCUSSION

Approximately only 50 cases reported in the literature and none of these cases were diagnosed as schwannoma preoperatively. CT scan is often useful to establish pancreatic lesion which usually demonstrate hypodense lesion with encapsulation CONCLUSION: Although the incidence of pancreatic schwannoma is low, it must be considered as one possibility in the differential diagnosis of mass lesions in the pancreas and whenever possible especially in large tumors surgical resections should be considered due to increased chance of transformation to malignancy.

Pictorial Review of Rare Pancreatic Tumors and Tumor-Like Lesions

췌장에는 다양한 종류의 종양 및 종양 유사 병변들이 생길 수 있다. 이 가운데, 췌장선암은 췌장의 가장 흔한 종양으로서 일반적으로 췌장암이라고 하면 이 종양을 가리킨다. 최근에는 영상 검사의 기술적 진보와 이용이 증가하면서 췌장의 희귀 종양 및 종양 유사 병변들의 발견 빈도가 증가하고 있다. 췌장의 드문 종양 및 종양과 유사한 병변들은 치료 방침과 예후가 췌장선암과 다르기 때문에 이들 질환의 감별은 임상적으로 중요한 의의가 있다. 영상 검사는 포상세포암이나 신경초종 등의 희귀 종양 및 자가면역 췌장염 또는 염증성 거짓종양과 같은 종양 유사 병변들과 췌장선암의 감별 진단에 중요한 역할을 하지만 영상 소견만으로 이들 질환을 정확히 구분하는 것은 한계가 있다. 이 논문에서는 췌장에서 생길 수 있는 희귀 종양 및 종양 유사 병변들의 다양한 영상 소견들과 췌장선암과의 감별에 있어 도움이 되는 특징들을 제시하고자 한다.

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.

A Surgically Resected Pancreatic Schwannoma with Obstructive Jaundice with Special Reference to Differential Diagnosis from Other Cystic Lesions in the Pancreas

Pancreatic schwannomas are uncommon. About 60% of pancreatic schwannomas develop cystic lesions, and the differential diagnosis from other cystic pancreatic tumors is difficult. A 43-year-old man presented for evaluation of liver dysfunction detected during a medical checkup. Blood testing detected obstructive jaundice. A computed tomography scan revealed a well-defined polycystic tumor of about 5 cm at the pancreatic head. We performed surgical resection to treat the patient's symptoms and facilitate long-term management. Histopathological examination revealed spindle-shaped cells. Immunohistochemical studies showed S100 protein expression and the absence of CD34 and c-kit protein expression. Finally, we diagnosed a schwannoma. Pancreatic schwannoma is usually asymptomatic. The present case presented with obstructive jaundice, which is reportedly a rare symptom. Pancreatic schwannomas should be considered as a differential diagnosis of pancreatic cystic tumors. Dilatation of the pancreatic duct and the 18-fluorodeoxyglucose positron emission tomography findings are important for the differential diagnosis.

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.

Abdominal schwannomas: review of imaging findings and pathology

Schwannomas are typically slow growing, encapsulated benign neoplasms. Visceral schwannomas are rare, and preoperative diagnosis is challenging, as they are often confused with other neoplasms even with advanced imaging studies. Surgical excision is usually needed to establish a definitive diagnosis, as pathology is the "gold standard." We review the imaging findings of abdominal schwannomas focusing on pancreatic, gastrointestinal, and retroperitoneal/adrenal schwannomas with pathology correlation. We conclude that schwannoma should be included in the broad differential diagnosis of an abdominal mass and that when it is unnecessary radical resection can be avoided.