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

Comments and illustrations of the European Federation of Societies for Ultrasound in Medicine guidelines: Rare pancreatic tumors, ultrasound and contrast-enhanced ultrasound features-Malignant mesenchymal tumors

Rare malignant mesenchymal pancreatic tumors are systematized and reported in this review. The focus is on the appearance on imaging. The present overview summarizes the data and shows that not every pancreatic tumor corresponds to the most common entities of ductal adenocarcinoma or neuroendocrine tumor.

Rare Solid Pancreatic Lesions on Cross-Sectional Imaging

Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most common subtype is pancreatic ductal adenocarcinoma (PDAC), to a point that pancreatic cancer and PDAC are used interchangeably. But, in addition to PDAC, and to the other most common and well-known solid lesions, either related to benign conditions, such as pancreatitis, or not so benign, such as pancreatic neuroendocrine neoplasms (pNENs), there are solid pancreatic lesions considered rare due to their low incidence. These lesions may originate from a cell line with a differentiation other than exocrine/endocrine, such as from the nerve sheath as for pancreatic schwannoma or from mesenchymal cells as for solitary fibrous tumour. These rare solid pancreatic lesions may show a behaviour that ranges in a benign to highly aggressive malignant spectrum. This review includes cases of an intrapancreatic accessory spleen, pancreatic tuberculosis, solid serous cystadenoma, solid pseudopapillary tumour, pancreatic schwannoma, purely intraductal neuroendocrine tumour, pancreatic fibrous solitary tumour, acinar cell carcinoma, undifferentiated carcinoma with osteoclastic-like giant cells, adenosquamous carcinoma, colloid carcinoma of the pancreas, primary leiomyosarcoma of the pancreas, primary and secondary pancreatic lymphoma and metastases within the pancreas. Therefore, it is important to determine the correct diagnosis to ensure optimal patient management. Because of their rarity, their existence is less well known and, when depicted, in most cases incidentally, the correct diagnosis remains challenging. However, there are some typical imaging features present on cross-sectional imaging modalities that, taken into account with the clinical and biological context, contribute substantially to achieve the correct diagnosis.

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.

Pancreatic schwannoma: Case report, clinico-pathologic correlation, and review of the literature

Schwannomas are common peripheral nerve sheath tumors that typically occur on the head, neck, trunk, or extremities. Intra-abdominal schwannomas, however, are rare. We describe a young woman who presented for imaging evaluation of suspected nephrolithiasis and was incidentally found to have a schwannoma centered within the pancreatic parenchyma. In addition, we detail the clinical, imaging, and histopathologic features of pancreatic schwannoma and summarize diagnosis and management of this rare clinical entity.

Two giant connected retroperitoneal schwannomas: a rare case report

Schwannoma is a type of tumor originating from Schwann cells of peripheral nerves. In this study, we report a rare case of two giant connected retroperitoneal schwannomas. The patient presented to our department with a 1-day history of abdominal pain and without other symptoms. There were no abnormalities in the patient’s tumor markers. Abdominal plain computed tomography (CT) revealed two (combined) retroperitoneal masses appearing as soft tissue-density shadows with uneven internal density, cystic low-density shadows, and patchy calcification shadows. The larger mass measured approximately 12.0 cm × 12.3 cm in size. The tumors were completely excised by a reasonable surgical approach while the surrounding organs closely related to the tumor were preserved. Postoperative pathology confirmed that the tumors were benign schwannomas. In the 18-month follow-up, the patient had no recurrences and was asymptomatic. We summarize the diagnosis and treatment of two rare combined giant retroperitoneal schwannomas in a single patient. Laparotomy for the management of retroperitoneal giant schwannomas may be safe and effective.

Clinical presentation, management, and research progress of adrenal schwannoma

Objective

This study shares our experience in managing adrenal schwannoma (AS).

Methods

The clinical data of eight patients with AS in our hospital from April 2007 to April 2022 were analyzed retrospectively.

Results

A total of 1309 patients with adrenal lesions were treated in the affiliated hospital of Guizhou Medical University for 15 years, of which only 8 cases were diagnosed as AS, accounting for 0.61%. Among the eight patients with AS, there were five females and three males, with an average age of 48.63 ± 12.05 years, and the average maximum diameter of the tumor was 6.96 ± 1.83 cm. All patients underwent adrenalectomy and were pathologically diagnosed as AS after the operation. The average follow-up time of eight patients with AS was 60.13 ± 22.33 months, and there was no recurrence or metastasis.

Conclusion

The retroperitoneum is an uncommon site for schwannoma tumors, and among adrenal incidentalomas, the schwannoma is rare. The disease lacks specific clinical and imaging features, but correct diagnosis before the pathological examination is very important for clinical management and surgical decision. When imaging examination indicates a slow-growing retroperitoneal mass, schwannoma should be considered. Surgical resection is the main treatment. Pathology is the gold standard for diagnosis. Most of the tumors are benign and have a good prognosis. There is a risk of recurrence after the operation, and it should be monitored actively.

Gastric cancer with concurrent pancreatic schwannoma: A case report

BACKGROUND

The differential diagnosis of abdominal masses is somewhat troublesome, especially when there is a malignancy to be evaluated. We report herein a unique case of gastric adenocarcinoma concurrent with a pancreatic schwannoma. Correct assessment of intraoperative findings is essential for adequate tumor staging and to decide the proper management of a concurrent pancreatic lesion.

CASE SUMMARY

Computed tomography scan performed for gastric cancer staging revealed a solid and cystic pancreatic mass that had no signs of local invasiveness. Surgical resection of the pancreas was decided preoperatively since a radical approach of the gastric tumor could be performed. There were no signs of distant metastases, and the large pancreatic mass was in contact with the posterior gastric wall. Histopathological study revealed a pancreatic schwannoma, which is an uncommon neoplasm that arises from Schwann cells around peripheral nerves.

CONCLUSION

Therefore, pancreatic masses deserve special attention regarding the differential diagnosis in patients with gastric cancer. The presence of a large pancreatic mass should not preclude the potentially curative intent of the gastric cancer treatment.

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.

Gastrointestinal tract schwannomas and brief review of literature

Schwannomas originating from Schwann cells arise from the peripheral nerve sheath and are slow-growing, benign tumors that originate mostly from the mesenchyme. It appears equally in both sexes. Schwannomas are often seen in the 3rd and 5th decades of life. Schwannomas can be seen everywhere where peripheral nerves are seen. Gastrointestinal schwannomas constitute 2-6% of all submucosal masses, and the stomach is the most common region (60-70%). Endoscopic Ultrasound (EUS)-guided sampling of gastrointestinal submucosal lesions has made it possible to achieve preop- erative differential diagnosis. Patients diagnosed with gastrointestinal schwannomas between January 2005 and December 2017 were included in this study. Three out of six patients were females. Median age was 52.5 (44-76) years. Schwannomas were found in two patients in the gastric region, one patient in the appendiceal region, two patients in the colon and one patient in the perianal region. Primary schwannomas are usually benign. Radical resection with free margin is necessary because of the risk of malignant degeneration; chemo and radiotherapy response is indeterminate, and local recurrence rates are high.

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

Pancreatic Schwannoma Diagnosed by Endoscopic Ultrasound-guided Fine-needle Aspiration

A schwannoma is a tumor originating from Schwann cells. It is occasionally observed in the abdominal viscera in the form of a submucosal tumor derived from the gastric or duodenal muscularis propria. To date, only a few studies have reported on pancreatic schwannomas. Furthermore, very few patients are preoperatively diagnosed with pancreatic schwannoma because of the lack of established imaging characteristics distinguishing this type of schwannoma from other conditions. We herein report the first English publication of pancreatic schwannoma in which surgery was avoided because a pathological diagnosis was made solely on the basis of endoscopic ultrasound-guided fine-needle aspiration findings.

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.

Pancreatic Schwannoma with Cystic Degeneration: A Case Report and Literature Review

Schwannomas originate from Schwann cells, and they are the most common benign neoplasms of the peripheral nerves. They can occur in most parts of the body but have a predilection for the head, the neck, and the flexor aspects of the extremities. Pancreatic schwannomas are uncommon, and only a few cases have been reported in the English literature. Approximately two-thirds of pancreatic schwannomas undergo cystic degeneration, and they should be considered in the differential diagnosis of solid pancreatic tumors with cystic changes to facilitate accurate diagnosis and optimal treatment. We report a case of a pathologically proven schwannoma in the pancreatic tail with multiple cystic and hemorrhagic changes followed by a review of relevant literature.

Identification of Genomic Alterations in Sporadic Pancreatic Neurogenic Tumors

Pancreatic neurogenic tumors, including schwannoma and neurofibroma, are rare, and their genetic aberrances have not been defined. The present study aimed at investigating the genomic alterations of pancreatic schwannoma and neurofibroma. Two patients with pancreatic schwannoma and 1 patient with neurofibroma, who underwent surgical resection at the First Affiliated Hospital, Sun Yat-sen University between June 2016 and April 2019, were recruited into the study. Their tumor tissues were analyzed by exome sequencing and genome sequencing. Exome sequencing revealed a MUTYH likely pathogenic germline variant in 1 schwannoma with somatic NF2del and NOTCH1 amplification. Pathway enrichment analysis on the other schwannoma case showed that the main abnormal function involved DNA damage repair, mitosis, and cell cycle. In addition, genome sequencing showed the inversion (INV) variant of SPIRE gene and multiple mitochondrial INV variants in both schwannoma cases. Furthermore, exome sequencing revealed NF1del, single nucleotide variation, TP53, and ERBB3 amplification in neurofibroma, whereas genomic duplication/deletion variants and mitochondrial abnormalities were much less than that in schwannoma. In conclusion, variants in NF1 and NF2 genes, amplification of key driver genes, and somatic and mitochondrial INV variants may play important roles in the development of pancreatic schwannoma and neurofibroma.

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.

Retroperitoneal schwannoma sandwiched between abdominal aorta and inferior vena cava. A case report

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Retroperitoneal schwannomas in the abdominal cavity are rare and pose difficulty in preoperative diagnosis and management.

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Imaging modalities are usually not sufficient to conclude a diagnosis.

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EUS-FNA is useful to confirm preoperative diagnosis.

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In EUS-FNA, diagnosis can be accurate if the tumor size is small and tumor is devoid of intratumoral degenerations.

Introduction

Schwannomas are tumors that originate from the Schwann cells present in the nerve sheath of peripheral nerves. They are commonly seen in cephalocervical areas. Schwannomas in the abdominal cavity are rare. Here, we discuss a case of retroperitoneal schwannoma lying dorsal to pancreas with critical relations to surrounding vessels.

Presentation of case

A 74 years old asymptomatic male was found with elevated amylase level on his routine blood examination. MR imaging revealed retroperitoneal mass of size 21*18*24 mm. EUS-FNA confirmed retroperitoneal schwannoma. The patient had co-morbid renal disease and was on hemodialysis. During the latest follow up, the tumor was 41*37*41 mm in size located dorsal to the confluence of right renal vein and inferior vena cava. The tumor was in contact with inferior vena cava, horizontal part of duodenum, right renal artery, right kidney, and adrenal gland. The patient underwent laparotomy and the tumor was extract with intact capsule. There were no post-operative complications.

Discussion

Pre-operative diagnosis in retroperitoneal schwannomas is challenging because imaging features are usually non-specific, and biopsy is the only diagnostic technique. EUS-FNA, which has low diagnostic accuracy, is useful in pre-operative diagnosis of small tumors devoid of intra-tumoral degeneration.

Conclusion

Retroperitoneal schwannoma is a rare entity. Preoperative diagnosis and curative resection are technically difficult. Care should be given during preoperative investigations and surgical resection of the tumor. EUS-FNA can be a useful diagnostic tool.

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.

A case of primary pancreatic schwannoma diagnosed by endoscopic ultrasound-fine needle aspiration

Pancreatic schwannoma is difficult to diagnose preoperatively. A 79-year-old man was found to have a 9-mm pancreatic mass on abdominal ultrasonography. On EUS, there was a 9-mm, clearly demarcated, round, solid, hypo-echoic mass in the pancreatic body. The differential diagnosis included a pancreatic neuroendocrine tumor, a solid-pseudopapillary neoplasm, and an atypical pancreatic cancer. EUS-FNA was performed with a 22G needle. On pathology examination, spindle-shaped tumor cells were seen proliferating in bundles. On immunostaining, the lesion was negative for c-kit, CD34, and α-SMA but positive for S-100 protein. The MIB-1 index was < 2%. Based on the above findings, the lesion was diagnosed as a benign pancreatic schwannoma. We, therefore, decided to follow the patient with careful observation rather than resecting the lesion surgically. The tumor has not changed significantly after 3 years of follow-up. EUS-FNA is useful for the diagnosis of pancreatic schwannoma. If the tumor can be determined to be benign preoperatively, unnecessary surgery can be avoided. EUS-FNA should be actively implemented for pancreatic tumors that are difficult to diagnose definitively on imaging.

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.

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.

Computed tomographic characteristics of gastric schwannoma

Objective

This study aimed to characterize the computed tomographic (CT) features of gastric schwannoma (GS).

Methods

We retrospectively reviewed CT images of 19 cases of histologically proven GS between January 2010 and December 2015. Tumor location, size, contour, margin, growth pattern, and degree and pattern of enhancement, perigastric lymph nodes, ulceration, necrosis, and calcification were evaluated.

Results

GS was located in the gastric body (73.7%), gastric antrum (15.8%), and gastric fundus (10.5%), with a mean maximum diameter of 4.5 ± 1.8 cm. All tumors presented as oval, well-defined solid masses, with exophytic (36.8%), endoluminal (15.8%), or mixed (47.4%) growth patterns. Ulcers (57.9%) and perigastric lymph nodes (47.4%) were observed. Moderate enhancement (87.5%) was observed in the portal phase. Eighteen (94.7%) cases showed homogeneous enhancement.

Conclusions

GS typically presents as a mass in the stomach with an exophytic or mixed growth pattern, moderate homogeneous enhancement, and is prone to be accompanied by perigastric lymph node inflammatory reactive swelling. Larger GSs are more likely to be associated with ulcers.

Malignant peripheral nerve sheath tumor of the pancreas-A case report

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Pancreatic schwannoma arise from sympathetic and Para sympathetic fibers that cross pancreas.

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Macroscopically they are well circumscribed, encapsulated lesions, homogenous lesions.

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Microscopically they show Antoni A & B areas.

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They demonstrate S100, vimentin, CD56 positivity.

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Malignant transformation is extremely rare with only 8 reported cases till now.

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Treatment is simple enucleation, but a accurate pre-operative diagnosis is difficult to make hence a oncollogically margin negative resection is done.

Introduction: Nerve sheath tumors are tumors arising from nerve sheaths or which show nerve sheath differentiation. They are divided as benign and malignant. They are associated with Von Recklinghausen syndrome. Characterised by café-au-lait spots, lisch nodules, acoustic neuromas, pheochromocytomas.

Presentation of case: A 62 year old gentleman came with complaints of Abdominal discomfort for 1month. He also had Left sided abdominal pain, Anorexia, Vomiting, No history of dyspepsia, fever, bowel disturbance. Patient is a known case of diabetes mellitus II. On abdominal examination a large mass of 10*8 cms was palpated in the left hypochondrium, left lumbar, and umbilical region. It had restricted mobility, not moving with respiration, firm in consistency. On palpation of neck, the thyroid gland was found to be enlarged with palpable right lobe.

Contrast enhanced computed tomography showed large lobulated heterogenously enhancing mass with internal necrosis and calcifications in the left hypochondrium, in the region of distal body and tail of pancreas. There were no other foci of metastasis in abdomen or chest. Chest X-ray of patient was normal. Ultrasound of neck revealed a suspicious nodule in right lobe of thyroid measuring 1*1 cms with no nodal enlargement. Fnac of thyroid nodule was done under image guidance which was suggestive of papillary carcinoma of thyroid. As image guided biopsy of abdominal tumour could not be done patient was planned for laparotomy. The tumor was resected en bloc - distal pancreatectomy and splenectomy. Post opereative biopsy showed irregular spindle shaped cells with nuclei exhibiting “a wavy, buckled appearance” malignant peripheral nerve sheath tumor. Patient was reviewed after a period of 2 months. Positron emission tomography was done which revealed para aortic nodes and 2 mesenteric nodes. It also revealed a metabolically active nodule in thyroid with cervical nodal metastasis. Patient was taken up for total thyroidectomy with functional neck dissection. Histopathology confirmed papillary carcinoma of thyroid with positive lymph nodes. Patient was advised to undergo a radioactive iodine scan showed 0.3% uptake. Patient was started on chemotherapy for para aortic nodes with a regimen of paclitaxel, adriamycin, ifosumide and mesma.

Discussion: Pancreatic schwannoma arise from sympathetic and Para sympathetic fibers that cross over pancreas. Patients Present with abdominal pain and weight loss commonly. Macroscopically they are well circumscribed, encapsulated lesions, homogenous lesions. Microscopically they show Antoni A & B areas. They demonstrate S100, vimentin, CD56 positivity. Most common differential diagnosis are cystic mucinous / serous neoplasms of pancreas. Malignant transformation is extremely rare with only 8 reported cases till now. Treatment is simple enucleation, but a accurate pre-operative diagnosis is difficult to make hence a oncollogically margin negative resection is done. Adjuvant radiotherapy can be given to reduce the tumor load. Chemotherapy can be given with ifosumide and doxorubicin.

Conclusion: Malignant pancreatic nerve sheath tumours are very rare to be found, but have very poor prognosis, hence in cases of pancreatic tumour its better to keep the diagnosis of nerve sheath tumour also a differential diagnosis. In conclusion pancreatic tumours are to be identified at the earliest and surgery should be done for those cases

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.

A Case of Pancreatic Schwannoma Diagnosed Preoperatively by Endoscopic Ultrasonography-Guided Fine Needle Aspiration and Treated with Laparoscopic Surgery

Background: Pancreatic tumors are often difficult to diagnose in atypical cases, and a pancreatic schwannoma is very rare. We present a case of pancreatic schwannoma with calcification diagnosed preoperatively by endoscopic ultrasonography (EUS)-guided fine needle aspiration (FNA) and treated with laparoscopic distal pancreatectomy.

Presentation: A 72-year-old-woman was admitted to our hospital due to a 6 × 4.5 cm large tumor in the pancreatic tail. Imaging modalities revealed that the tumor was hypovascular and gradually enhanced with calcification, but was without cystic lesions. EUS revealed the tumor had a clear boundary with a low echoic mass. EUS-FNA was performed and spindle-shaped cells that were immunopositive for S-100 and negative for c-kit, CD34, and desmin were detected, resulting in a diagnosis of schwannoma. Laparoscopic distal pancreatectomy with splenectomy was safely performed without recurrence for a year.

Conclusions: Schwannoma is very rare; however, characteristics of the tumor, such as calcification, can help the diagnosis and, if possible, EUS-FNA should be performed for an appropriate treatment decision.

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.

Rare Tumors and Lesions of the Pancreas

There are a few entities that account for most solid and cystic masses of the pancreas. The pancreas harbors a wide array of diseases, including adenocarcinoma, and its variants, such as anaplastic and adenosquamous carcinoma. Other neoplasms include acinar cell carcinoma, solid pseudopapillary tumor, and sarcomas. Benign lesions include hamartomas, hemangiomas, lymphangioma, and plasmacytoma. Isolated metastases include renal cell carcinoma, melanoma, and other carcinomas. Benign inflammatory conditions, such as autoimmune pancreatitis and groove pancreatitis can also mimic solid neoplasms of the pancreas.

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.

A case of pancreatic schwannoma showing increased FDG uptake on PET/CT

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Pancreatic schwannoma is rare and preoperative diagnosis is difficult due to the lack of specific symptoms, radiological characteristics and tumor markers.

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Incidental detection of pancreatic schwannoma is predicted to increase due to the widespread use of CT and MRI. It is important to take into account this tumor in the differential diagnosis of pancreatic tumors.

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We should be aware that FDG-PET/CT shows abnormal accumulation in a benign pancreatic schwannoma.

Introduction

Schwannomas are neoplasms originating from Schwann cells in nerve sheath, but pancreatic schwannomas are rare.

Presentation of case

A 59-year-old female incidentally pointed out a 2-cm-sized solid mass in the pancreas head by computed tomography (CT) which was performed for other reasons. Magnetic resonance imaging (MRI) showed a mass with hypointensity on T1-weighted images and a heterogenous hyperintensity on T2-weighted images. Magnetic resonance cholangiopancreatography (MRCP) showed no abnormal findings in the main pancreatic duct. The mass of the pancreas head showed a significantly increased uptake on fluorin-18 fluorodeoxyglucose positron emission tomography CT (FDG-PET/CT). Based on the radiological findings, a malignant potential tumor was preliminarily considered. Subtotal stomach-preserving pancreatoduodenectomy (SSSPD) was performed to make a definite diagnosis. The resected specimen showed a well-encapsulated circumscribed mass, measuring 2.0 cm, in the pancreas head. Histopathological examination revealed proliferation of spindle cells showing interlacing and palisading patterns in the tumor. The proliferating cells showed no atypia and few mitoses. Immunohistochemically, the spindle cells were positive for S-100 protein. The Ki67 labeling index was approximately 2%. Based on these findings, a diagnosis of benign schwannoma of the pancreas was made.

Conclusion

Although pancreatic schwannoma is a rare neoplasm, it is important to take into account this tumor in the differential diagnosis of pancreatic tumors. In addition, we should be aware that FDG-PET/CT shows abnormal accumulation in a benign pancreatic schwannoma.

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.

Primary mesenchymal tumors of the pancreas in a single center over 15 years

In total, 95% of primary tumors in the pancreas are epithelial tumors; primary mesenchymal tumors at this site are extremely rare. At present, only one comprehensive study about these rare tumors has been performed. Another retrospective analysis of these rare tumors is performed in the present study, which, to the best of our knowledge, is the first to be performed in China. In the present study, 10 patients that underwent resection for primary mesenchymal tumors of the pancreas were identified in a 15-year period at the Chinese Academy of Medical Sciences and Peking Union Medical College, which accounted for 0.51% of the total surgically resected primary tumors of the pancreas at this hospital. Among the 10 patients, 7 patients (70%) were diagnosed with benign/borderline tumors, and the remaining 3 patients (30%) were diagnosed with malignant tumors. It was a unique finding of the present study that the preoperative diagnosis was frequently a misdiagnosis, in terms of the specific pathological diagnosis. Therefore, although primary mesenchymal tumors of the pancreas are extremely rare, they should be considered in order to make the correct preoperative diagnosis. Contrarily to a previous study, in the present study, the most common benign tumor was not desmoid tumor, but solitary fibrous tumors; the most frequent primary sarcoma was not undifferentiated/unclassified sarcoma either. In conclusion, the present study aids the understanding of these rare tumors; however, primary mesenchymal tumors of the pancreas require additional exploration in the future.

Pancreatic schwannoma: A rare case and a brief literature review

INTRODUCTION

Pancreatic schwannoma (PS) is an extremly rare benign tumor. Less than 50 cases of pancreatic schwannoma have been described in the English literature over the past thirty years.

PRESENTATION OF CASE REPORT

A 63-year-old female underwent left modified radical mastectomy 2 years ago due to breast cancer. During her routine check-up, a 65×63×55mm measured calcified, well-demarcated, cystic-mass having septations and calcifications that localized to the pancreatic head was detected by abdominal computerized tomography. She was asymptomatic and her tumor markers were in normal ranges. A standard Whipple procedure was performed, and the histo-pathological diagnosis of the resected specimen was reported as ancient schwannoma with clear surgical margins. Patient's postoperative course was eventful. She had a biliary leakage after surgery which was managed conservatively. She is under follow-up.

DISCUSSION

Pancreatic schwannoma also known as neurilemoma or neuroma is a slowly growing, encapsulated, mostly benign tumor with smooth well-delineated margins that originates from myelin producing schwann cells located on the nerve sheath of the peripheral epineurium of either the sympathetic or parasympathetic autonomic fibers. PS's are extremly rare. The head of pancreas being involved in the vast majority of cases (40%), followed by its body (20%). Management of pancreatic schwannomas remains largely controversial. Both enucleation and radical surgical resections have revealed great therapeutic efficiency. with a well prognosis without recurrences.

CONCLUSION

Although rare, PS's should be considered in the differential diagnosis of the other solid or cystic masses of the pancreas.

Common and uncommon pitfalls in pancreatic imaging: it is not always cancer

Despite advances in multimodality imaging of pancreas, there is still overlap between imaging findings of several pancreatic/peripancreatic disease processes. Pancreatic and peripancreatic non-neoplastic entities may mimic primary pancreatic neoplasms on ultrasound, CT, and MRI. On the other hand, primary pancreatic cancer may be overlooked on imaging because of technical and inherent factors. The purpose of this pictorial review is to describe and illustrate pancreatic imaging pitfalls and highlight the basic radiological features for proper differential diagnosis.

Enlarging Pancreatic Schwannoma: A Case Report and Review of the Literature

A 72-year-old female presented with dyspepsia for 2 years and an incidental mass in the head of the pancreas on abdominal computed tomography (CT) scan. Patient had multiple negative endoscopic ultrasound guided biopsies. She was followed up for 3 years with serial imaging until an abdominal CT scan showed an increase in size of the pancreatic mass. Physical examination was unremarkable. Laboratory tests including tumor markers were normal. Given the enlarging size of the mass and its impingement on the portal vein, the consensus was to proceed with surgery. Histology revealed a 3.5 cm mass showing a spindle cell neoplasm with mild atypia. The lesion was well defined and nerve tissue was noted at the periphery. On immuno-stains, the spindle cells were positive for S-100 protein and negative for pan-cytokeratin, CD-34, CD-117, smooth muscle actin and Melan A, consistent with the diagnosis of a pancreatic schwannoma.

Diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration cytology of pancreatic lesions

BACKGROUND

Endoscopic ultrasound-guided fine needle aspiration cytology (EUS-FNAC) is currently the most commonly used procedure for obtaining cytologic specimens of the pancreas. It is accurate, minimally invasive, safe and cost-effective. However, there is discrepancy between cytological and surgical diagnoses. This study was aimed at evaluating the diagnostic accuracy of EUS-FNAC of the pancreas.

METHODS

We performed a retrospective review of 191 cases of pancreatic lesions initially diagnosed by EUS-FNAC with subsequent histological diagnosis between 2010 and 2012 in the Department of Pathology, Seoul National University Hospital. Cytologic and surgical diagnoses were categorized into five groups: negative, benign, atypical, malignant, and insufficient for diagnosis. Subsequently, 167 cases with satisfactory yield in both surgical and cytology specimens were statistically analyzed to determine correlations with diagnosis.

RESULTS

In comparison to surgical diagnoses, cytologic diagnoses were true-positive in 103 cases (61.7%), true-negative in 28 cases (16.8%), false-positive in 9 cases (5.4%), and false-negative in 27 cases (16.1%). The diagnostic accuracy was 78.4%, sensitivity was 79.2%, and specificity was 75.7%. The positive predictive value was 92.0%, and negative predictive value was 50.9%.

CONCLUSIONS

EUS-FNAC has high accuracy, sensitivity, specificity and positive predictive value. Overcoming the limitations of EUS-FNAC will make it a useful and reliable diagnostic tool for accurate evaluation of pancreatic lesions.

Primary mesenchymal tumors of the pancreas: single-center experience over 16 years

OBJECTIVE

Primary mesenchymal tumors of the pancreas are extremely rare and no comprehensive study of this class of tumors has been previously performed.

METHODS

Twenty cases of the primary mesenchymal tumors of the pancreas were selected and compared clinicopathologic variables with consecutively resected 500 pancreatic ductal adenocarcinomas.

RESULTS

Finally, 20 (0.3%) cases were confirmed as primary mesenchymal tumors. The 14 (70%) cases of benign/borderline tumors included 4 cases of fibromatoses, 2 cases of cavernous hemangiomas, 2 cases of schwannomas, 2 cases of solid and cystic hamartomas, 2 cases of solitary fibrous tumors, 1 case of inflammatory myofibroblastic tumor, and 1 case of angiomyolipoma. The 6 (30%) cases of sarcomas comprised 3 cases of undifferentiated/unclassified sarcomas, 1 case of leiomyosarcoma, 1 case of Ewing sarcoma/primitive neuroectodermal tumor, and 1 case of atypical lipomatous tumor/well-differentiated liposarcoma. When compared with the 500 ductal adenocarcinomas, the 3 surgically resected sarcomas were larger (mean, 5.8 cm vs 3.6 cm; P = 0.02); however, no difference in median survival time was observed between patients with sarcoma (23 months) and patients with ductal adenocarcinoma (16 months).

CONCLUSIONS

First, primary mesenchymal tumors of the pancreas are extremely rare. Second, several primary mesenchymal tumor types can be observed in the pancreas. Understanding these rare disease entities will help ensure their correct diagnosis.

Pancreatic schwannoma - a rare case report

Pancreatic schwannomas are rare neoplasms. Only 47 cases have been reported in literature as of date. Age group that is commonly involved varies between the range of 20-87 years, with an almost equal sex ratio. Tumour size ranges from 1-20 cm. Locations where schwannomas can be encountered in the pancreas are in the vast majority, the head and body, the incidence being: head-40 %, junction of head and body-6 %, body-21 %, body and tail-15 %, tail-4 % and uncinate process-13 %, 60 % of the tumours are cystic, the rest being solid tumours. We hereby report a case where in total gastrectomy with distal pancreatectomy and splenectomy was done for carcinoma stomach involving the stomach bed and pancreatic schwannoma was an incidental finding in this case.

A case of pancreatic schwannoma - The features in imaging studies compared with its pathological findings: Report of a case

Pancreatic schwannoma is a very rare tumor that tends to be confused with other pancreatic tumors preoperatively. We report a case of schwannoma of the pancreatic head. A 40-year-old woman was admitted to our hospital for treatment of a pancreatic tumor which was found by medical checkup. It was a well-defined solid tumor exhibiting heterogeneous enhancement with some necrotic foci on contrast-enhanced computed tomography (CT) and on magnetic resonance imaging (MRI). Angiography and CT during arteriography revealed the main feeding arteries of the tumor to be the posterior and anterior superior pancreaticoduodenal arteries. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) showed accumulation of FDG in the tumor with a maximum standardized uptake value of 3.6. We diagnosed a solid pseudopapillary neoplasm or a pancreatic neuroendocrine tumor preoperatively and performed pylorus-preserving pancreaticoduodenectomy. The tumor had well a well-defined capsule and was composed of a large solid portion containing spindle cells and a smaller hemorrhagic portion containing hypocellular stroma, and diagnosed as pancreatic schwannoma by immunohistochemistry. In this case, CT during arteriography was useful in determining the origin of the tumor. MRI reflected the pathological features of the tumor. The most important finding was that FDG-PET showed abnormal accumulation of FDG in the benign pancreatic schwannoma.

Primary pleural benign myxoid schwannoma in an 18-year-old female: a case report and literature review

Pleural schwannomas are exceedingly rare neoplasms of the thoracic cavity. To the best of our knowledge, less than 20 cases have been reported in the medical English literature. Herein, we report the case of primary pleural benign myxoid schwannoma in an 18-year-old female. The patient was originally referred to our tertiary care hospital for further management of right adrenal gland mass. Physical examination and all laboratory tests were normal. Contrast-enhanced computed tomography scan showed a 4.2 × 3.2 cm, heterogeneous noncalcified mass involving the right adrenal gland region. The right renal vein and inferior vena cava were intact. There was no pleural effusion, ascites, or lymphadenopathy. No pelvic masses were identified. Patient was scheduled for surgical resection. On laparotomy, the mass was not found in its radiologically expected location, and the right kidney and right adrenal gland were intact. The right-sided lower part of diaphragm was opened, and the mass was interestingly found inside the thorax attached to the pleura, and resected successfully. A final histopathological diagnosis of primary pleural benign myxoid schwannoma was established. At a postoperative 6-month followup, there was no radiological evidence of tumor recurrence. Furthermore, literature review on pleural schwannomas is also presented.

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.

Schwannomatosis presenting as pancreatic and submandibular gland schwannoma

Schwannomatosis is a well-established third form of neurofibromatosis, characterized by the presence of multiple non-vestibular, non-intradermal schwannomas, often associated with chronic pain. Herein, we report a 41-year-old man with a history of paternal neurofibromatosis 1, who presented with partially cystic tumors in the pancreas and in the right submandibular gland. Besides, he complained of neuropathic pain in the right inguinal and suprapubic area. Magnetic resonance imaging revealed multiple intradural-extramedullary tumors at the cervical, thoracic and lumbar spinal canal, suggestive of schwannomas. The vestibular nerves were not involved. Pathological examination of the glandular tumors disclosed benign schwannomas. These tumors had substantial myxoid stroma and prominent cystic change, and showed a mosaic pattern of loss of INI1/SMARCB1 expression by immunohistochemistry. Later, the patient developed three nodules in the right lung which were interpreted as schwannomas. To our knowledge, this is the first report of schwannomatosis presenting as pancreatic and salivary gland schwannomas.