Diagnosis Of Solid Pseudopapillary Neoplasm Research Articles

ABCD1 as a Novel Diagnostic Marker for Solid Pseudopapillary Neoplasm of the Pancreas.

The diagnosis of solid pseudopapillary neoplasm of the pancreas (SPN) can be challenging due to potential confusion with other pancreatic neoplasms, particularly pancreatic neuroendocrine tumors (NETs), using current pathological diagnostic markers. We conducted a comprehensive analysis of bulk RNA sequencing data from SPNs, NETs, and normal pancreas, followed by experimental validation. This analysis revealed an increased accumulation of peroxisomes in SPNs. Moreover, we observed significant upregulation of the peroxisome marker ABCD1 in both primary and metastatic SPN samples compared with normal pancreas and NETs. To further investigate the potential utility of ABCD1 as a diagnostic marker for SPN via immunohistochemistry staining, we conducted verification in a large-scale patient cohort with pancreatic tumors, including 127 SPN (111 primary, 16 metastatic samples), 108 NET (98 nonfunctional pancreatic neuroendocrine tumor, NF-NET, and 10 functional pancreatic neuroendocrine tumor, F-NET), 9 acinar cell carcinoma (ACC), 3 pancreatoblastoma (PB), 54 pancreatic ductal adenocarcinoma (PDAC), 20 pancreatic serous cystadenoma (SCA), 19 pancreatic mucinous cystadenoma (MCA), 12 pancreatic ductal intraepithelial neoplasia (PanIN) and 5 intraductal papillary mucinous neoplasm (IPMN) samples. Our results indicate that ABCD1 holds promise as an easily applicable diagnostic marker with exceptional efficacy (AUC=0.999, sensitivity=99.10%, specificity=100%) for differentiating SPN from NET and other pancreatic neoplasms through immunohistochemical staining.

Solid pseudopapillary neoplasm of the pancreas during pregnancy presenting as gastrointestinal stromal tumor: A case report and review of literature

Solid pseudopapillary neoplasm (SPN) is a rare tumor that can complicate pregnancy. More than its rarity, SPNs are unique neoplasms because of their obscure histogenesis, cytology, immunohistochemical profile, and imaging characteristics. This report describes the case of a 32-year-old gravida 2 para 1 (1001) seen at 24 weeks with an intra-abdominal mass. The patient presented with a long-standing history of abdominal mass with the working impression of gastrointestinal stromal tumor. We employed a multidisciplinary approach to closely monitor tumor growth, ensure maternal and fetal well-being, avert complications, and avoid unnecessary clinical interventions. Histopathological evaluation and immunohistochemistry studies of representative specimens taken at the time of delivery revealed the diagnosis of SPN of the pancreas. Based on a review of local search engine databases, this is the first documented case of SPN complicating pregnancy in the Philippines.

EUS-guided tissue acquisition in patients with solid pseudopapillary neoplasms of the pancreas

ABSTRACT Objectives Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has been the most common method used for the preoperative cytopathological diagnosis of solid tumors of the pancreas. There are only a few reported cases about the role of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) in the pre-operative diagnosis of solid pseudopapillary neoplasms (SPN). This study aimed to evaluate the diagnostic yield of EUS-TA,including endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) andEUS-FNB, in patients with SPN. Methods We performed a retrospective analysis of patients with EUS-TA for SPN diagnosis in 2 referral centers. The primary outcome was the diagnostic yield of EUS-TA compared to the surgical specimen. Results Seventy-four patients with SPN of the pancreas were identified. Eighteen had a EUS-TA (10 EUS-FNB and 8 EUS-FNA). The median age of the patients was 31 years (IQR 21–38), and all patients were women. The most common presenting symptom was abdominal pain. Most of the tumors were in the head of the pancreas (9/18; 50%). The median tumor size by EUS was 4.5 cm (min-max 2–15 cm). The most common appearance on EUS was a solid lesion (n = 8/18, 44.4%). A definitive presurgical cytopathological diagnosis was obtained in 16/18 patients (88.8%) with EUS-TA. The sensitivity and positive predictive value of the EUS-TA were 94% each. One patient in the EUS-FNB group developed mild acute pancreatitis. Conclusion The diagnostic yield of the EUS-TA in SPN is high. In most cases, the diagnosis was obtained with the first procedure. No differences in the diagnostic yield or AEs between EUS-FNA vs. EUS-FNB needles were seen.

CT target scanning in the diagnosis of solid pseudopapillary tumor of the pancreas

ObjectiveTo discuss the value of computed tomography (CT) iterative reconstruction technique combined with target scanning in the diagnosis of solid pseudopapillary tumor of the pancreas (SPTP).MethodsThe clinical information and CT examination data of 27 patients with SPTP were retrospectively analyzed, and the general condition and CT performance of the patients were observed. The CT image reconstruction algorithm of all patients used iterative reconstruction technique combined with the application of target scanning technique.ResultsA total of 27 patients were included in this study, including 6 males and 21 females, aged 14–72 years with a mean age of 39.6 ± 13.6 years. SPTP was more common in young and middle-aged females, with a low level of tumor markers, dominated by cystic-solid tumors. The combination of CT iterative reconstruction technology and targeted scanning revealed the following: the capsule of SPTP was clear and complete, where calcifications were visible, solid components were progressively enhanced, and rare pancreatic and bile duct dilation was seen. Tumors were cystic-solid in 18 of 27 patients with SPTP, of which the solid components showed isodensity or slightly low-density, with calcifications. The solid components and cyst walls were mildly enhanced during the arterial phase, and were progressively enhanced during the parenchymal phase, portal vein phase, and delayed phase, with their enhancement degree lower than that of normal pancreatic parenchyma, and pancreatic and bile duct dilation was rare. There were no statistical differences in tumor location, morphology, growth pattern, integrity of capsule, cystic or solid, calcifications, and enhancement features between the male group and the female group (P > 0.05).ConclusionThe iterative reconstruction combined with target scanning clearly displayed the CT features of tumors, helping the diagnosis and clinical treatment of the disease.

Role of endoscopic ultrasound in the characterization of solid pseudopapillary neoplasm of the pancreas.

Solid pseudopapillary neoplasm (SPN) is an uncommon pathology of the pancreas with unpredictable malignant potential. Endoscopic ultrasound (EUS) assessment plays a vital role in lesion characterization and confirmation of the tissue diagnosis. However, there is a paucity of data regarding the imaging assessment of these lesions. To determine the characteristic EUS features of SPN and define its role in preoperative assessment. This was an international, multicenter, retrospective, observational study of prospective cohorts from 7 large hepatopancreaticobiliary centers. All cases with postoperative histology of SPN were included in the study. Data collected included clinical, biochemical, histological and EUS characteristics. One hundred and six patients with the diagnosis of SPN were included. The mean age was 26 years (range 9 to 70 years), with female predominance (89.6%). The most frequent clinical presentation was abdominal pain (80/106; 75.5%). The mean diameter of the lesion was 53.7 mm (range 15 to 130 mm), with the slight predominant location in the head of the pancreas (44/106; 41.5%). The majority of lesions presented with solid imaging features (59/106; 55.7%) although 33.0% (35/106) had mixed solid/cystic characteristics and 11.3% (12/106) had cystic morphology. Calcification was observed in only 4 (3.8%) cases. Main pancreatic duct dilation was uncommon, evident in only 2 cases (1.9%), whilst common bile duct dilation was observed in 5 (11.3%) cases. One patient demonstrated a double duct sign at presentation. Elastography and Doppler evaluation demonstrated inconsistent appearances with no emergence of a predictable pattern. EUS guided biopsy was performed using three different types of needles: Fine needle aspiration (67/106; 63.2%), fine needle biopsy (37/106; 34.9%), and Sonar Trucut (2/106; 1.9%). The diagnosis was conclusive in 103 (97.2%) cases. Ninety-seven patients were treated surgically (91.5%) and the post-surgical SPN diagnosis was confirmed in all cases. During the 2-year follow-up period, no recurrence was observed. SPN presented primarily as a solid lesion on endosonographic assessment. The lesion tended to be located in the head or body of the pancreas. There was no consistent characteristic pattern apparent on either elastography or Doppler assessment. Similarly SPN did not frequently cause stricture of the pancreatic duct or common bile duct. Importantly, we confirmed that EUS-guided biopsy was an efficient and safe diagnostic tool. The needle type used does not appear to have a significant impact on the diagnostic yield. Overall SPN remains a challenging diagnosis based on EUS imaging with no pathognomonic features. EUS guided biopsy remains the gold standard in establishing the diagnosis.

The Role of MRI in the Diagnosis of Solid Pseudopapillary Neoplasm of the Pancreas and Its Mimickers: A Case-Based Review with Emphasis on Differential Diagnosis.

Solid pseudopapillary neoplasm (SPN) is rare pancreatic tumor occurring most commonly in young females. The typical imaging appearance of SPN is of well-defined, encapsulated, and large heterogeneous tumors, consisting of solid and cystic components due to various degrees of intralesional hemorrhage and necrosis. However, atypical imaging presentation in the form of small solid tumors or uniformly cystic lesions might also be seen, which can be explained by specific pathological characteristics. Other imaging features such as a round shape, the absence of main pancreatic duct dilatation, and slow growth, in combination with vague symptoms, favor the diagnosis of SPNs. Nevertheless, the radiological findings of SPN might overlap with other solid and cystic pancreatic neoplasms, such as neuroendocrine tumors, serous and mucinous neoplasms, and even small pancreatic adenocarcinomas. In addition, a few benign non-tumorous conditions including walled-of-necrosis, and intrapancreatic accessory spleen may also pose diagnostic dilemmas simulating SPNs on imaging studies. The aim of this manuscript is to provide a comprehensive overview of the typical and atypical imaging features of SPNs and to describe useful tips for differential diagnosis with its potential mimickers.

The differential diagnosis of pancreatic cystic neoplasms with conventional ultrasound and contrast-enhanced ultrasound.

Advances in imaging have improved the detection rate of pancreatic cystic neoplasms (PCNs), but clinical management varies depending on the pathological type of PCNs, and thus accurate differential diagnosis is of considerable clinical significance. We conducted this study to identify the clinical and sonographic features of PCNs with significance for differential diagnosis and to compare the diagnostic accuracy of conventional ultrasound and conventional ultrasound combined with contrast-enhanced ultrasound (CEUS) for PCNs. From January 1, 2011, to December 31, 2022, a total of 100 patients with PCNs who underwent CEUS examination and were confirmed to have PCNs by postoperative pathology in West China Hospital of Sichuan University were included in this study. Of the clinical characteristics of PCNs, age and gender were found to be important differential diagnostic features. Moreover, communication of the lesion with the main pancreatic duct on conventional ultrasound and CEUS images was a critical feature in the differential diagnosis of intraductal papillary mucinous neoplasm (IPMN). The size of the lesion, the thickness of the cyst wall and the number of septa in conventional ultrasound images, the uniformity of the cyst wall thickness in CEUS images, and the enhancement pattern in the arterial phase were significant features for the differential diagnosis of serous cystic neoplasm (SCN). Cyst wall thickness and uniformity of the cyst wall thickness in conventional ultrasound images and cyst wall thickness and septa thickness in CEUS images were important features in the differential diagnosis of mucinous cystic neoplasm (MCN). The size and internal components of the lesion on conventional ultrasound images, internal components of the lesion, and the enhancement pattern in the arterial phase and rim enhancement on CEUS images were the key features in the differential diagnosis of solid pseudopapillary neoplasm (SPN). Conventional ultrasound combined with CEUS demonstrated significantly greater accuracy than did conventional ultrasound alone in the differential diagnosis of PCNs (66% vs. 79%; P=0.002). PCN types differ in their clinical and ultrasound features. Conventional ultrasound combined with CEUS can better distinguish between different pathological types of PCNs than can conventional ultrasound alone.

Presumed radiological diagnosis of solid pseudopapillary tumors: do we really know what we are watching?

ObjectivesLittle is known about the clinicians’ ability to ascertain the identity of a pancreatic lesion as solid pseudopapillary tumors (SPT)preoperatively. We led this retrospective study to figure out the disease spectrum that mimic SPT, the key features of SPT and the accuracy of CT and MRI in characterizing them. MethodsRadiological and clinical database at a tertiary pancreatic disease center (Peking Union Medical College Hospital) was searched for patients who received CT or MRI with a presumed radiological diagnosis of SPT. Those patients’ clinical information and final pathological diagnosis were collected. ResultsDuring 2018.10–2021.12, 200 patients had a presumed radiological diagnosis of SPT, and 132 of them had unambiguous pathological diagnosis. SPT were confirmed in only 63.6% (84/132), while the others had a variety of neoplastic and nonneoplastic lesions, including pancreatic neuroendocrine tumors (n = 15), pseudocysts (n = 4), mucinous cystic neoplasms (n = 4), serous cystadenomas (n = 3), neural sheath tumors (n = 3), lymphoepithelial cysts (n = 2), and several very rare pathologies (n = 17). Of note, 11.4% (15/132) of those were benign or nonneoplastic lesions, while 6.8% (9/132) were neoplasms with highly aggressive nature, or pancreatic metastases, which require systematic evaluation and staging instead of upfront surgery. Retrospective radiological analysis based on key imaging features, clinical history and laboratory findings had an improved diagnostic accuracy of 78.5% with CT and 77.8% with MRI. ConclusionsThere is a broad disease spectrum mimicking SPT at CT and MRI. Key imaging features, clinical information and laboratory findings must be integrated to improve the diagnostic accuracy.

Central Pancreatectomy for Solid Pseudopapillary Tumour of Pancreas in A 13-Year Girl.

Solid Pseudopapillary Tumour (SPT) is a very rare tumour of the pancreas. A13-year girl presented to us with the complaint of upper abdominal pain and non-bilious vomiting for 15 days. Preoperative diagnosis of SPT involving the body of the pancreas was made by CT scan and ultrasound- guided Trucut biopsy. A sparingly rare procedure of central pancreatectomy with distal pancreatico-jejunostomy was performed. This procedure offers excellent results in benign and low-grade malignant pancreatic neck and body tumours. In addition, it preserves functional elements of the pancreas and also eliminates the infective and haematological effects of splenectomy. Key Words: Solid pseudopapillary tumour, Central pancreatectomy, Pancreatic tumours.

Age in combination with gender is a valuable parameter in differential diagnosis of solid pseudopapillary tumors and pancreatic neuroendocrine neoplasm

BackgroundThe clinicopathological characteristics of solid pseudopapillary tumor (SPT) and pancreatic neuroendocrine neoplasm (pNEN) are different. We, therefore, systematically investigated the performance of the clinicopathological characteristics in distinguishing SPT from pNEN.MethodsWe collected the cases from the Surveillance, Epidemiology, and End Results Program. The International Classification of Diseases for Oncology, third edition (ICD-O-3) for tumors was used to identify patients with pNEN or patients with SPT. To determine the performance of age in combination with gender in distinguishing SPT from pNEN, a nomogram was developed and the performance of this nomogram was evaluated by the receiver operating characteristic curve and the area under the curve (AUC).ResultsIn the training cohort, 563 patients with pNENs and 30 patients with SPTs were recruited. The logistic regression and receiver operating characteristic curves suggest that age, gender, T-stage, N-stage, and M-stage could discriminate SPT and pNEN. The AUC of age, gender, T-stage, N-stage, and M-stage was 0.82, 0.75, 0.65, 0.69, and 0.70, respectively. Based on the nomogram, we observed that the AUC of age and gender is significantly high than that of the T-stage, N-stage, and M-stage.ConclusionsThe present study proposes a non-invasive nomogram that could aid in the differential diagnosis of pNEN and SPT. This might help the clinicians to distinguish SPT from pNEN and choose the appropriate treatments for the patients.

Spontaneous regression in solid pseudopapillary neoplasm of pancreas.

A solid pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm that mainly occurs in young women. We herein report the case of spontaneous regression in SPN of the pancreas. A 48-years-old female was found to have a mass in the head of the pancreas on examination for her back pain and referred to our hospital in 20XX. Laboratory data showed no abnormalities in serum levels of pancreatic enzymes and tumor markers. A contrast CT scan of upper abdomen showed a slightly enhanced lesion (23 × 19mm in diameter) without cystic component or fibrous capsule in the head of the pancreas. An MRI scan showed the mass as low-intensity in T1-WI and high-intensity in T2-WI. She admitted to our hospital for further examination of a pancreatic mass by EUS-FNA in 20XX + 4. EUS showed a slightly hypoechoic mass (30 × 19mm in diameter) compared with the neighboring normal pancreas. Tumor margin was relatively clear and the internal echo image was homogenous. Histological findings revealed a solid and pseudopapillary proliferation of eosinophilic polygonal cells with oval nuclei. The tumor cells were positive for vimentin and CD10 in the cytoplasm and β-catenin in the nuclei, which led to the diagnosis of SPN. We recommended this patient to undergo surgical resection, however, the patient chose follow-up examinations. Follow-up study after 1 year using MRI scan showed spontaneous regression, which was coincided with her menopause. These findings suggest that the natural regression of SPN may occur and female sex hormone changes may regulate the growth of SPN.

Solid Pseudopapillary Tumor of the Pancreas with Node Invasion: What to do? A Case Report and Literature Review

Solid Pseudopapillary Neoplasms (SPN) of the pancreas are rare neoplasms representing 1-2% of all pancreatic tumors, and considered as low-grade malignancies. This pathology mainly affects young women. Its prognosis is usually excellent when the tumor is limited to the pancreas, with a cure rate greater than 95% after a complete surgical resection. Preoperative diagnosis is always difficult. SPNs can be metastatic. Hepatic and lymph node localizations are the most reported in the literature. The recurrence rate after surgical resection is 3-9%. We report the case of a 36-year-old patient who was complaining of abdominal pain for 2 months. An abdominal contrast-enhanced Computed Tomography (CT) scan showed a solido-cystic mass of the tail of the pancreas. The patient underwent laparoscopic radical antegrade modular pancreatosplenectomy. The diagnosis of SPN with lymph node metastasis was confirmed by histopathology and immunohistochemistry, requiring adjuvant chemotherapy.

Multicenter Study on the Performance of Imaging Tests Compared to Endosonography-Guided Fine-Needle Aspiration in the Diagnosis of Solid Pseudopapillary Neoplasms of the Pancreas

Introduction: Imaging diagnosis of pancreatic solid-pseudopapillary neoplasms (SPNs) is difficult. Preoperative diagnosis by endosonography-guided fine-needle aspiration (EUS-FNA) is possible and has been reported in the literature in pancreatic tumors. However, its usefulness is still controversial. The aim of this study was to determine the accuracy of the EUS-FNA in the diagnosis of patients with SPN and describe the findings in computerized tomography (CT), magnetic resonance cholangiopancreatography imaging (MRI/MRCP), and EUS therefore comparing the imaging methods alone to the findings of microhistology (McH) obtained by EUS-FNA. Materials and Methods: We retrospectively reviewed the medical records of patients undergoing EUS-FNA with suspected SPN in imaging studies in 5 Brazilian high-volume hospitals (two university hospitals and three private hospitals). The demographic data; findings in CT, MRI/MRCP, and EUS; and McH results obtained by EUS-FNA were noted prospectively. The final diagnosis was obtained after the anatomopathological examination of the surgical specimen in all patients (gold standard), and we compared the results of CT, MRI/MRCP, EUS, and the McH with the gold standard. Results: Fifty-four patients were included in the study, of which 49 (90.7%) were women with an average age of 33.4 (range 11–78) years. The most common symptom presented was abdominal pain, present in 35.2% patients. SPN was detected incidentally in 32 (59%) patients. The average size of the tumors was 3.8 cm (SD: 2.26). The most common finding at EUS was a solid, solid/cystic, and cystic lesion in 52.9%, 41.1%, and 7.8% patients, respectively. The final diagnosis was 51 patients with SPN and 3 with nonfunctioning pancreatic neuroendocrine tumors (NF-NET). The correct diagnosis was made by CT, MRI/MRCP, EUS isolated, and EUS-FNA in 21.9%, 28.88%, 64.71%, and 88.24%, respectively. EUS-FNA associated with CT and MRI increased diagnostic performance from 22.72% to 94.11% and from 29.16% to 94.11%, respectively. Conclusions: SPN are rare, incidentally identified in most cases, and affect young women. Differential diagnosis between SPN, NF-NET, and other types of tumors with imaging tests can be difficult. EUS-FNA increases preoperative diagnosis in case of diagnostic doubt and should be used whenever necessary to rule out NF-NET or other type of solid/cystic nodular lesion of the pancreas.

The role of confocal endomicroscopy for diagnosis of solid pseudopapillary tumor of the pancreas.

The role of confocal endomicroscopy for diagnosis of solid pseudopapillary tumor of the pancreas.

Solid Pseudopapillary Neoplasm: A Single Institutional Case Series of a Rare Pancreatic Tumor.

Purpose:Solid pseudopapillary neoplasms (SPN) are rare pancreatic cystic neoplasms with low malignant potential that tend to occur in young women. Due to the rarity of this disease, there are few large case series in the literature, and the exact pathophysiology remains unknown. In this article, we aim to share our institutional experience.Methods:Retrospective clinical data collection and analysis was performed on all patients with a diagnosis of SPN at the University of Colorado Hospital and Children's Hospital of Colorado (n = 28).Results:Twenty-eight patients were diagnosed with SPN during the study period. The median age was 21.5 years, and the majority of patients were female (89.3%) and Caucasian (60.7%). Six patients were diagnosed incidentally (21.4%). The majority of tumors were in the pancreatic tail (46.4%), and most underwent distal pancreatectomy (64.3%). The mean tumor size was 5.4 cm, and R0 resection was achieved in 25 patients (89.3%). Ten patients underwent laparoscopic resection (35.7%). The median hospital length of stay was 8.5 days, and postoperative complication rate was 39.3%. Median follow-up was 41 months, with 78.6% of patients alive without evidence of disease, while 2 patients were lost to follow-up. Two patients developed recurrence/metastases, which were resected; both are alive without evidence of disease.Conclusion:SPN are rare pancreatic tumors diagnosed most frequently in young women. Surgical resection is the mainstay of treatment, and outcomes are excellent if complete resection is achieved. Predictors of malignant disease are inconsistent in current literature. Considerations should be made for a minimally invasive approach in patients with SPN. Multidisciplinary clinics may be helpful in the diagnosis, management, and surveillance of pancreatic cystic lesions, with major potential for the advanced practitioner role.

Solid pseudopapillary neoplasm of pancreas presenting after bicycle handlebar injury: diagnostic pitfalls in a young female-A case report.

Introduction and importanceSolid pseudopapillary neoplasm (SPN) of pancreas is a rare neoplasm with very low malignant potential. It mainly affects females in third decade of life and has favourable prognosis.Case presentationWe report a case where a 17-years old girl presented with history of blunt abdominal trauma with handlebar of bicycle 6 months back, following which she developed abdominal pain and fullness in epigastrium. Keeping pancreatic pseudocyst as provisional diagnosis, she was investigated. The final diagnosis of SPN of pancreas came as a surprise.The mass, about 6x5cm, was excised and Roux-en-Y distal pancreatico-jejunostomy was done.Clinical discussionPatient showed no recurrence or metastasis till one year of follow-up. This is the first case report of SPN presenting after handlebar injury.ConclusionTimely and adequate resection provides good long-term survival.

Role of endoscopic ultrasonography in the diagnosis of solid pseudo-papillary neoplasm: Egyptian multi-centric case series and systematic review

Solid pseudo-papillary neoplasm (SPPN) is a rare type of pancreatic tumor accounting for less than 2% of all pancreatic neoplasms. Accurate diagnosis of these tumors is very important for proper management. In this study, observations were documented from 18 consecutive cases diagnosed with SPPN using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The data of 18 consecutive cases were prospectively collected and reviewed. The collected data included age, gender, symptoms, size and site of the lesion, and type of surgery performed, in addition to mortality and recurrence rates.The mean age of the included cases was 33 years, and most of them were females (94.44%). Abdominal pain was the common symptom, and the pancreatic body was the most affected site. EUS-FNA confirmed the diagnosis in all cases when compared to the surgical specimen obtained. Cases were treated either with pancreatico-duodenectomy or distal pancreatectomy. One case (1/18) had early postoperative mortality due to sepsis. The remaining cases developed no recurrence or metastasis during the follow-up period of 18 months.SPPN is not a common pancreatic tumor. Confirming the diagnosis plays a crucial role prior to surgery as it facilitates intraoperative planning; therefore, EUS-FNA is a golden standard method used to diagnose. Postoperative survival has improved if the tumor is completely removed. EUS-FNA technique is a minimally invasive technique that can provide high yielding in providing detailed diagnostic analysis of SPPN.

Utility of SOX11 for the diagnosis of solid pseudopapillary neoplasm of the pancreas on cytological preparations.

The diagnosis of solid pseudopapillary neoplasm (SPN) on fine needle aspiration specimens can be challenging because of morphological overlap with other pancreatic neoplasms, including pancreatic neuroendocrine tumour (PanNET). SRY-related high-mobility group box 11 (SOX11) is a recently described sensitive and specific marker for SPN diagnosis. However, SOX11 immunocytochemistry on cytological smears has not been reported. We evaluated the utility of SOX11 for diagnosis of SPN on cytological preparations. SOX11 immunocytochemistry was performed on Papanicolaou-stained smears and/or corresponding cell blocks from aspirates of 7 SPN and 10 PanNET cases identified between 2005 and 2020. Findings were compared with those for beta-catenin, a frequently used diagnostic marker for SPN. Six smears and 6 cell blocks from SPN cases and 8smears and 10 cell blocks from PanNET cases were available for immunostaining. For SPN, nuclear staining for SOX11 was seen in 6 of 6 (100%) smears and 5 of 6 (83%) cell blocks, with equivocal staining in 1 cell block. In contrast, 7 of 8 (88%) smears and 9 of 10 (90%) cell blocks were negative for SOX11 for PanNet, with equivocal staining seen in 1 case. Beta-catenin immunocytochemistry showed nuclear staining in 6 of 7 (86%) SPN cases and no staining in all 10 (100%) PanNET cases. SOX11 detected by immunocytochemistry can serve as a useful diagnostic marker for SPN, in addition to beta catenin, and can be performed on cytological smears in cases without a cell block preparation.

S1521 Solid Pseudopapillary Neoplasm: Case Report of a Rare Pancreatic Tumor

Introduction: Solid pseudo-papillary neoplasm (SPN) is a rare low-grade malignant cystic exocrine neoplasm of the pancreas with a distinctive pathologic architecture. It is usually diagnosed incidentally, and complete resection is mainly curative with excellent long-term prognosis despite a small malignant potential. Case Description/Methods: A 28 yo female with history of lumbar disc herniation and subsequent micro-discectomy, presented to the emergency department with a 1-day history of severe left upper quadrant abdominal pain, nausea, and vomiting. She denied any other symptom or previous trauma. On physical examination, the abdomen was soft with mild tenderness in LUQ, and no rebound or palpable mass. Lab evaluation showed a mild leukocytosis (16.5K), but otherwise liver tests and pancreatic enzymes were within normal limits. CT scan showed an obstructing ureteral calculus and a large 7.1 cm incidental mass in the pancreatic tail with chronic splenic vein occlusion. MRCP later confirmed a 6.8 x 7.5 x 7.7 cm heterogeneous but well defined/encapsulated arising from the pancreatic tail/distal body. The lesion had heterogeneous enhancement, diffusion restriction, and areas of T1 hyperintensity. The patient successfully underwent a laparoscopic distal pancreatectomy and splenectomy and was discharged home after 3 days. Pathology confirmed the suspected diagnosis of SPN of the pancreas with samples negative for foci of malignancy. Immuno-histochemical stains revealed tumor cells to be positive for beta-catenin, cyclin D1, CD10 and synaptophysin, while negative for chromogranin. Discussion: SPN is considered a low-grade malignant pancreatic tumor according to the WHO Classification of Digestive System Tumors, with reported malignant transformation of around 15-16%. Despite this, SPN still has a generally excellent long-term prognosis. SPNs have a characteristic appearance on cross-sectional imaging, appearing as a mixed solid and cystic pancreatic lesion, however cytologic analysis is usually done for confirmation of the diagnosis. The use of pre-operative biopsy or EUS-FNA has been controversial and is felt to be of limited benefit. In our patient, the post-operative cytologic diagnosis after surgery proved valuable for establishing the diagnosis with no need for pre-operative EUS-FNA. Treatment usually is surgical resection, which is curative; appropriate clinical follow-up is warranted due to risk of local recurrence. There is no clear role for systemic chemotherapy, hormonal therapy, or radiotherapy.Figure 1.: A. MRI abdomen and pelvis with contrast T2 Coronal showing a heterogenous well defined and encapsulated partially exophytic mass arising from the pancreatic tail/distal body. B. Axial LAVA (3D T1 weighted sequence with Fat Suppression) pre-contrast. C. LAVA post-contrast Figure 2-D. Solid sheet of uniform tumor cells showing focal loosely cohesive pseudopapillary architecture (Hematoxylin & Eosin, x 100). E. Nuclear and cytoplasmic immunoreactivity for B-catenin (B-catenin immunohistochemical stain, x 200).

Solid Pseudopapillary Neoplasm of the Pancreas in Males: A Rare Case and Literature Review

Even with the increase in recent years in the diagnosis of Solid Pseudopapillary Neoplasm of the Pancreas (SPN) [1,2] it is still considered a rare pathology and represents around 2% of pancreatic tumors.