Features Of Solid Pseudopapillary Neoplasm Research Articles

Liquid-based cytology features of pancreatic acinar cell carcinoma: comparison with other non-ductal neoplasms of the pancreas.

Acinar cell carcinoma (ACC) is a rare malignant epithelial neoplasm, which shares many cytomorphological features with other non-ductal pancreatic neoplasms such as pancreatic neuroendocrine neoplasm (PanNEN) and solid-pseudopapillary neoplasm (SPN). Due to the relative rarity of these tumors, pathologists are less familiar with the cytological features, especially on liquid-based cytology (LBC) which has been relatively recently introduced for endoscopic ultrasound-guided fine needle aspiration specimens. We evaluated the detailed cytological features of 15 histologically confirmed ACC (7 conventional smears [CS], 8 LBC), and compared them with the LBC features of SPN (n = 9) and PanNEN (n = 9). Compared with CS, LBCs of ACC demonstrated significantly less bloody background. All ACCs demonstrated prominent nucleoli and macronucleoli on LBC. On comparison with the LBC features of SPN and PanNEN, most ACCs demonstrated a necrotic background with apoptotic debris while PanNEN and SPN did not show these features. Acinar structures were predominantly observed in ACC, while frequent pseudopapillary structures were seen only in SPN. Prominent nucleoli and macronucleoli were only seen in ACC. ACC had characteristic cytological features that could be observed on LBC preparations, such as high cellularity, necrotic/apoptotic background, nuclear tangles, acinar arrangement of cells, and macronucleoli. These findings also help distinguish ACC from PanNEN and SPN on LBC. It is important to be familiar with these features, as an accurate diagnosis on endoscopic ultrasound-guided fine needle aspiration cytology would have impact on the management of the patient.

Imaging differentiation of solid pseudopapillary neoplasms and neuroendocrine neoplasms of the pancreas

PurposeThe present study aimed to compare the computed tomography (CT) and magnetic resonance imaging (MRI) features of solid pseudopapillary neoplasms (SPNs) and pancreatic neuroendocrine neoplasms (pNENs). MethodLesion imaging features of 39 patients with SPNs and 127 patients with pNENs were retrospectively extracted from 104 CT and 91 MRI scans. ResultsCompared to pNEN patients, SPN patients were significantly younger (mean age 51.8 yrs versus 32.7 yrs) and more often female (female: male ratio, 5.50:1 versus 1.19:1). Most SPNs and pNENs presented as well-defined lesions with an expansive growth pattern. SPNs more often appeared as round or ovoid lesions, compared to pNENs which showed a lobulated or irregular shape in more than half of cases (p<0.01). A surrounding capsule was detected in the majority of SPNs, but only in a minority of pNENs (<0.01). Hemorrhage occurred non-significantly more often in SPNs (p=0.09). Signal inhomogeneity in T1-fat-saturated (p<0.01) and T2-weighted imaging (p=0.046) as well as cystic degeneration (p<0.01) were more often observed in SPNs. Hyperenhancement in the arterial and portal-venous phase was more common in pNENs (p<0.01). Enlargement of locoregional lymph nodes (p<0.01) and liver metastases (p=0.03) were observed in some pNEN patients, but not in SPN patients. Multivariate logistic regression identified the presence of a capsule (p<0.01), absence of arterial hyperenhancement (p<0.01), and low patient age (p<0.01), as independent predictors for SPN. ConclusionsThe present study provides three key features for differentiating SPNs from pNENs extracted from a large patient cohort: presence of a capsule, absence of arterial hyperenhancement, and low patient age.

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.

Solid pseudopapillary neoplasm of the pancreas.

Solid pseudopapillary neoplasms are rare. This article reviews the clinical and pathologic features of solid pseudopapillary neoplasm of the pancreas, including the epidemiology, cytology, molecular pathology, differential diagnosis, treatment, and prognosis. Solid pseudopapillary neoplasms are low-grade malignant tumours of the pancreas characterized by poorly cohesive epithelial cells with solid and pseudopapillary patterns. Solid pseudopapillary neoplasms occur predominantly in young women. Although solid pseudopapillary neoplasms can occur throughout the pancreas, they arise slightly more frequently in the tail of the pancreas. The aetiology is unknown. Extremely rare cases have been reported in the setting of familial adenomatous polyposis. There are no symptoms unique to solid pseudopapillary neoplasms, however, the most common symptom is abdominal pain or discomfort. The features of solid pseudopapillary neoplasms on computed tomography imaging are indicative of the pathologic changes within the tumour. Typically, well-demarcated masses with variably solid and cystic appearances. Microscopically, these tumours are composed of epithelial cells forming solid and pseudopapillary structures, frequently undergoing haemorrhagic cystic degeneration. Typically, these tumours express nuclear and/or cytoplasmic β-catenin. Almost all solid pseudopapillary neoplasms harbour mutations in exon 3 of CTNNB1, the gene encoding β-catenin. The overall prognosis is excellent, and most patients are cured by complete surgical resection.

English

BACKGROUND Solid pseudopapillary neoplasm (SPN) of pancreas is a rare epithelial tumour of low malignant potential. SPN accounts for less than 1 to 2 % of exocrine pancreatic tumours. It mainly affects women between the second and third decade of life, and its management is not well defined. The aim of this study was to report clinicopathological characteristics of SPN and its outcome. METHODS A retrospective study was conducted in a tertiary care centre from January 2015 to December 2019. All patients who were diagnosed and treated as SPN of pancreas in our institute were retrospectively reviewed. A data of the characteristics of these patients was developed, including age, gender, size, location of tumour, treatment, histopathological and immunohistochemical features. RESULTS Six patients were diagnosed as having SPN of pancreas, during the 5-year period. All 6 patients were female. Youngest age of occurrence was 15 years. Maximum age was 41 years. Average age was 25 years. All patients were symptomatic and the most common symptom was dull aching upper abdominal pain. Contrast enhanced computed tomography (CECT) was done for all patients. 3 patients had typical features of SPN. Endoscopic ultrasound (EUS) was done for 4 patients and EUS fine needle aspiration cytology (FNAC) was done for 3 patients. Patients were provided with procedure details and informed consent was taken. All patients were subjected to surgical treatment. Out of six patients, two underwent laparoscopic spleen preserving distal pancreatectomy, two patients underwent classical Whipple’s procedure and two patients had undergone median pancreatectomy. CONCLUSIONS SPN are rare neoplasms, typically affecting young females without clear histogenesis and with a malignant potential. Appearance from imaging studies can be adequate to guide surgical resection without pre-operative pathological assessment. But in unclear cases, EUS-FNAC with immunohistochemistry helps in establishing a pre-operative diagnosis. Surgical resection should be offered when feasible. Prognosis of SPN of the pancreas is good due to its favourable biological features, even in the presence of distal metastasis. KEYWORDS Solid Pseudopapillary Neoplasm (SPN)

Pancreatic Solid Pseudopapillary Neoplasm: Key Pathologic and Genetic Features.

Solid pseudopapillary neoplasm of the pancreas is a low-grade malignant tumor generally associated with a good prognosis. Solid pseudopapillary neoplasms show peculiar morphologic features, but sometimes the differential diagnosis with other pancreatic neoplasms (ie, pancreatic neuroendocrine tumors) can be a challenging task, especially in cytologic or biopsy specimens. In these cases immunohistochemistry is a useful tool, but the diagnostic utility of several proposed immunohistochemical markers is questionable. In recent years, despite several attempts to characterize the pathogenetic, molecular, and prognostic features of solid pseudopapillary neoplasms, they still remain unclear. To give the reader a comprehensive update on this entity. The PubMed database (US National Library of Medicine) was searched using the following string: pseudopapillary tumor [AND/OR] neoplasm [AND/OR] pancreas. All articles written in English were included. In addition, because a heterogeneous terminology has been used in the past to define solid pseudopapillary neoplasms, the reference lists of each paper selected in the PubMed database were also reviewed. This review gives a comprehensive update on the pathologic, clinical, and molecular features of solid pseudopapillary neoplasms, particularly addressing issues and challenges related to diagnosis. In addition, we have tried to correlate the molecular alterations with the morphologic and clinical features.

Clinical and Pathological Features of Solid Pseudopapillary Neoplasms of the Pancreas: A Nationwide Multicenter Study in Japan.

The aim of this study was to evaluate the clinicopathological features of solid pseudopapillary neoplasms (SPNs). In this retrospective study, 288 SPNs were analyzed. Overall, 214 patients (74%) were female. Distant metastases occurred in 4 patients, and splenic vein tumor thrombus occurred in 1 patient. Although imaging findings showed large (>2.0 cm) SPNs with clear, regular border, and heterogeneous internal structure, small SPNs appeared as almost entirely solid. Surgical resection was performed in 278 cases. The 5-year survival rate was 98.8%. Six patients had tumor recurrence after the initial resection. The detection rate in typical pathological findings was low for small SPNs. Tumor extension to the pancreatic parenchyma was detected in greater than 70% of the cases. Tumor invasion to adjacent organs was detected in 13 cases. One was given a diagnosis of apparent high-grade malignant transformation. The proportion of male cases was higher than that in previous studies, and there were statistically significant differences in the onset age and tumor diameter between male and female patients. Therefore, women seemed to have an early occurrence of SPNs, suggesting a difference in the developmental stage between men and women. Images and pathological findings of SPNs varied according to tumor size. Our findings indicated that SPN patients have excellent survival after margin-negative surgical resection.

Solid pseudopapillary neoplasms of the pancreas do not express major pancreatic markers in pediatric patients

Solid pseudopapillary neoplasms (SPNs) of the pancreas are classified as "exocrine" pancreatic tumors by the World Health Organization. However, despite numerous studies using immunohistochemistry, electron microscopy, animal models, and molecular biology, the histogenesis of SPN remains unclear. At the same time, our knowledge of human pancreas development has significantly increased. It is now well known that the undifferentiated PDX1+ pancreatic progenitors proliferate and differentiate into endocrine, ductal, and acinar cells, thanks to the expression of numerous transcription factors, which can be used to better characterize pancreatic tumors. In a series of 14 pediatric SPN, we investigated the expression of 4 transcription factors associated with pancreatic development (PDX1, SOX9, PTF1A, and NKX2.2) to obtain new insights into the pathogenesis of SPN. In addition, we tested the expression of different markers of epithelial, endocrine, exocrine, and neural differentiation using both immunohistochemical and immunofluorescence analyses. All tumors displayed the typical histologic features of SPN, with both pseudopapillary and solid patterns. The immunoprofile was characterized by immunoreactivity for β-catenin (100%), progesterone receptor (100%), cyclin D1 (100%), synaptophysin (65%), and S100 (15%). In all cases, tumor cells were negative for the following markers: PDX1, SOX9, PTF1A, NKX2.2, chromogranin A, glucagon, insulin, somatostatin, ghrelin, pancreatic polypeptide, amylase, GFAP, calretinin, EPCAM, and estrogen receptor α. To conclude, SPNs do not express major transcription factors involved in pancreatic development and differentiation, which does not allow for precise pancreatic lineage of tumor cells. Thus, additional studies are still required to determine the origin of SPN.

Clinical and Magnetic Resonance Imaging Features of Solid Pseudopapillary Tumor of the Pancreas in Male Patients.

Objective To analyze the clinical and magnetic resonance imaging(MRI)findings of solid pseudopapillary tumor(SPT)of the pancreas in male patients. Methods Clinical and MRI features of 51 patients with pathologically-proved SPT were retrospectively analyzed.The following MRI features of the lesions were analyzed:location,maximal diameter,shape,margin,capsule,solid and cystic components,signal intensity characteristics,and enhancement patterns.Results The average maximal diameter of the SPT in male patients was significantly smaller [(3.9±1.6)cm vs.(6.3±3.9)cm,P=0.035]than that of SPT in female patients.Pure solid tumors were signiciantly more common in male patients(8/14)than in female patients(9/37)(P=0.037).T1-weighted images of SPT showed mainly homogenous hypo-intensity in male patients(11/14)and heterogeneous hypo-intensity in female patients(23/37)(P=0.001).Hemorrhage was more prevalent in female patients(22/37)than in male patients(2/14)(P=0.005).There were no significant differences between male and female patients regarding clinical features and other magnetic resonance features(P>0.05).Conclusions On MRI,SPT in male patients is small and shows mainly pure solid component with rare hemorrhage.The clinical and other MRI features of SPT are not different between males and females.

Clinical and pathological features of solid pseudopapillary neoplasm (SPN) of the pancreas: A retrospective review of cases at Mayo Clinic.

e15757 Background: SPN is a rare neoplasia of the pancreas, defined by the World Health Organization (WHO) as an epithelial low-grade malignant neoplasm, with a high-grade malignant transformation potential. Literature in this subject is scarce and limited only to small retrospective series. Methods: This is a retrospective study aiming to characterize patients with the diagnosis of SPN at Mayo Clinic between 1992 and 2016. Demographics, clinical and pathological features, recurrence rate and overall survival were recorded. Malignant SPN was defined as per the WHO 2010 classification (Perineural invasion, angioinvasion or deep tissue invasion) and compared to Benign SPN. Results: 44 patients with SPN were identified. 39 patients (88.6%) were female. Median age at diagnosis was 27.5 (Range: 13-64). The most frequent presentation was abdominal pain (52.6%), whereas 36.8% were diagnosed based on incidental imaging findings. Majority (60.4%) of the tumors were located at the pancreatic tail, and 48.5% were solid-cystic lesions. Vascular and lymph node involvement were infrequent. 15 cases (30.23%) were classified as malignant. Tumor size was associated with malignant behavior (Table). Three patients had a metastatic presentation. All but 1 patient were treated with surgery. R1 resection was more frequent in malignant SPN, and 2 patients experienced disease recurrence. Two Stage IV patients were treated with surgery and experienced long term survival, one of them without evidence of disease. There was only 1 death recorded. Conclusions: SNP presents predominantly on young women. The prognosis is excellent even in presence of malignant features, and a complete surgery remains as the main treatment. [Table: see text]

Solid pseudopapillary neoplasm of the pancreas: CT imaging features and radiologic-pathologic correlation.

We aimed to evaluate the imaging features of solid pseudopapillary neoplasm (SPN) of the pancreas with an emphasis on radiologic-pathologic correlation. Ten patients (all female; mean age, 32 years) with histologic or cytologic diagnosis of SPN encountered between January 2007 and December 2013 were included in this study. Preoperative computed tomography (CT) images were reviewed for location, attenuation, enhancement pattern, margin, shape, size, morphology, presence of capsule and calcification. CT appearances were correlated with histopathologic findings. Tumors in the distal pancreatic body and tail had a tendency to be larger (mean size 12.6 cm vs. 4.0 cm). Six of the nine tumors that were resected had a fibrous pseudocapsule at histology, five of which could be identified on CT scan. Eight lesions had mixed hypoenhancing solid components and cystic areas corresponding to tumor necrosis and hemorrhage. The two smallest lesions were purely solid and nonencapsulated. Varied patterns of calcification were seen in four tumors. Three of the four pancreatic tail tumors invaded the spleen. At a median follow-up of 53 months, there was no evidence of recurrence in the nine patients who underwent surgical resection of the tumor. A mixed solid and cystic pancreatic mass in a young woman is suggestive of SPN. However, smaller lesions may be completely solid. Splenic invasion can occur in pancreatic tail SPNs; however, in this series it did not adversely affect the long-term outcome.

Retrospective analysis of clinicopathological features of solid pseudopapillary neoplasm of the pancreas

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm that accounts for 2–3% of all primary pancreatic neoplasms. This study aimed to characterize clinicopathological features associated with SPNs and to retrospectively evaluate the relationship of these features with predictive parameters associated with aggressive behavior. We reviewed 16 cases of SPN of the pancreas that had been diagnosed between 2005 and 2014 at our pathology department. A total of 16 cases, 15 female and one male, were evaluated in this study. The patient age ranged from 13 years to 63 years with a median of 35.70 years. The mean tumor diameter ranged from 2 cm to 18 cm with a mean diameter of 5.90 cm. We identified a significant association between the presence of clear cells and perineural invasion (p=0.019), which was considered to be a predictive factor for aggressive behavior. Other features (i.e., localization, nuclear grooves, central hyalinization, myxoid stroma, eosinophilic bodies, foamy histiocyte aggregates, multinucleated cells, and calcification) were not significantly associated with predictive factors for aggressive behavior. One patient died as a result of a pancreatic fistula that developed as a postoperative complication. The remaining 15 patients are alive and have not demonstrated any signs of recurrence or metastasis. The current study suggested that the presence of clear cells might serve as a possible prognostic indicator of perineural invasion, which is a predictive parameter associated with aggressive behavior in SPN.

Less Aggressive Surgical Procedure for Treatment of Solid Pseudopapillary Tumor: Limited Experience from a Single Institute.

ObjectivesTo evaluate the clinical characteristics and radiological features of solid pseudopapillary tumor (SPT) and assess surgical therapy strategy.MethodsA retrospective review was performed in 62 patients pathologically confirmed of SPT treated between 2003 and 2014. The clinical features, radiological examinations and surgical strategies were analyzed.Results56 females and 6 males were included in this study, mean age was 26 years old (range: 8–66 years old) with mean size of the tumor was 7.2 cm (range: 3–15 cm), and most tumor were commonly located in the head of pancreas (n = 29). Among all the cases, 3 patients had liver metastasis and underwent resection of SPT and liver metastasis. Furthermore, we performed 29 cases of local tumor excision; other patients underwent pancreaticoduodenectomy, middle pancreatectomy, middle pancreatectomy with splenectomy, distal pancreatectomy with spleen preservation, distal pancreatectomy with splenectomy and duodenum-preserving pancreatic head resection. No patient suffered from lymph node metastases. After median follow-up of 46 months (range: 2–135 months), no mortality or local recurrence or distant metastasis was found.ConclusionsSolid pseudopapillary tumor is a latent malignant tumor with excellent prognosis. If feasible, less aggressive resection without regular lymphadenectomy is recommended for treatment of patients with SPT.

Comparison of MR imaging features of solid pseudopapillary neoplasm of pancreas between male and female patients

PurposeTo evaluate MR imaging features of solid pseudopapillary neoplasms (SPN) in male patients and to compare them with the MR imaging features in female patients. Materials and methodsFifty patients who were histologically confirmed as SPN (M:F=8:42, mean age=36.4 years) with preoperative MRI were included. The following imaging features were reviewed: size, location, shape, margin, encapsulation, solid-cystic ratio, pancreatic duct dilatation, parenchymal atrophy, T1 signal intensity, T2 signal intensity, and morphological and dynamic pattern of enhancement. The statistical differences between male and female patients were analyzed. ResultsThe average age of male patients (50.8±4.1 years) was significantly higher (p<0.01) than female patients (33.7±2.0 years). The shape of SPN in male patients was predominantly lobulated (n=6/8, 75.0%) compared to female patients, in whom oval shaped SPN was most prevalent (n=26/42, 61.91%) (P=0.02). SPN in male patients contained less cystic component (solid, n=4/8, 50.0%; mainly solid, n=4/8, 50.0%) while cystic (n=5/42, 11.90%) or mainly cystic (n=13/42, 30.95%) lesions were significantly more prevalent in female patients (P=0.03). The majority of SPNs in both groups showed progressive heterogeneous enhancement pattern. Other MR imaging features showed no significant differences between the male and female patients. ConclusionOn MRI, SPN in male patients appeared as mainly solid mass with a lobulating contour and heterogeneous progressive enhancement occurring at an older age than female patients. Recognition of imaging features of SPN in male patients compared to typical SPN in female patients should assist in correct differentiation of SPN from other pancreatic tumors.

Sex differences in immunohistochemical expression and capillary density in pancreatic solid pseudopapillary neoplasm.

Solid pseudopapillary neoplasm (SPN) is a rare and low-grade malignant pancreatic neoplasm. Solid pseudopapillary neoplasm is rare in men, and most SPN cases are in young women. This study aimed to investigate sex differences in SPN clinical histopathology including capillary density and expression of immunochemical markers, including glypican 3. A total of 22 resected tumors from pancreatic SPN patients, including 16 women (73%) and 6 men (27%), were analyzed histopathologically and immunohistochemically for synaptophysin, β-catenin, estrogen receptor, progesterone receptor, Ki-67, CD10, CD31, and glypican 3. The median age was 52.5 years in men and 24 years in women (P = .046). The median tumor size was 22.5 mm in men and 40 mm in women (P = .337). In 11 of the 16 women (69%), but in none of the men, tumors showed complete or incomplete fibrous cap`sules (P = .006). Cholesterol clefts were observed in tumors from 10 women (63%) but in none from the men (P = .012). No significant sex differences were noted in tumor characteristics, including size, macroscopic cystic degeneration, necrosis, lymphovascular involvement, and perineural invasion. The SPNs were weakly positive for glypican 3, although there was no significant difference between sexes. Capillary density tended to be lower in tumors from men than in those from women, but not significantly. Thus, except for the fibrous capsule and cholesterol clefts often found in tumors and the younger age of the women, there were no significant sex differences in histopathologic or immunohistochemical features of SPN, despite its markedly higher occurrence in women.

Solid pseudopapillary neoplasm of the pancreas associated with familial adenomatous polyposis.

A man in his thirties visited our hospital for an evaluation of a 12×10-mm pancreatic solid tumor that was accidentally detected on computed tomography performed for follow-up of familial adenomatous polyposis (FAP). We diagnosed the patient with a solid pseudopapillary neoplasm (SPN) based on endoscopic ultrasound-guided fine-needle aspiration, and he underwent pancreaticoduodenectomy. Small SPN tumors appear as solid tumors, without typical features of SPN, making the definitive diagnosis more difficult. The genetic background of FAP patients can predispose them to SPN, and imaging of the pancreas should be performed at prescribed intervals in FAP patients.

Clinical and Pathological Features of Solid Pseudopapillary Neoplasms of the Pancreas at a Single Institution

Aims: The aim of this study was to determine the clinicopathological features and surgical management of solid pseudopapillary neoplasms (SPNs) of the pancreas at a single institution. Methods: We investigated 34 patients (5 males and 29 females) who underwent surgery for pathologically confirmed SPNs between 1994 and 2012. Results: Clinical symptoms were absent in 58.8% of the patients. The median tumor diameter was 42.7 mm. All tumors were successfully removed by R0 resection. Pathologically, 5.9% had duodenum invasion and 2.9% had pancreatic serosal invasion, but there was no lymph node metastasis. Radiological findings showed calcification in 39.4% of the patients, capsule formation in 51.5%, cystic components in 69.7%, solid components in 93.9% and internal bleeding in 36.4%. Immunohistochemically, neuron-specific enolase was positive in 100% of the patients, nuclear accumulation of β-catenin in 100% and CD10 in 78.8%. There were no recurrences reported at the median follow-up (67 months). Regarding gender differences, the cystic component in radiological imaging was the only significant finding among the features studied (p = 0.01). Conclusions: R0 resection with appropriate procedures appears to be sufficient for patients with SPNs, even for locally invasive tumors. There were no significant differences between genders except for the cystic component on radiological imaging.

MRI features of solid pseudopapillary neoplasm of the pancreas.

To evaluate the magnetic resonance imaging (MRI) findings of solid pseudopapillary neoplasm (SPN) of the pancreas. From January 2006 to December 2013, 41 patients with SPN of the pancreas were retrospectively evaluated. Inclusion criteria were the execution of an MR examination and tumor resection with an histopathological evaluation at our Institute. Exclusion criteria were the execution of an MR examination at other centers (14/41) and the execution of CT or ultrasonography (10/41) at our Institute. The qualitative analysis evaluated: location (head/body-tail), shape (round/oval/lobulated), margins (regular/irregular), and signal intensity on T1- and T2-weighted images compared to the surrounding pancreas (hypo-, iso-, or hyperintense and homogeneous or heterogeneous), appearance of MPD and the secondary ducts, and the presence of metastases and/or vascular involvement. The quantitative analysis included: maximum size of the lesion, wall thickness, and maximum diameter of the main pancreatic duct (MPD). The population comprised 17 women (median age: 31year) with a median tumor size of 50.6mm, a median wall thickness of 2mm and median diameter of the MPD of 1.8mm. 9/17 were at the head; 8/17 on the body/tail: respectively, 8/17 round, 6/17 oval, and 3/17 lobulated. All showed regular margins. On T1-weighted images8/17 appeared homogeneously hypointense, 7/17 heterogeneously hypointense, and 2/17 heterogeneously hyperintense. On T2-weighted images1/17 appeared homogeneously hyperintense and 16/17 heterogeneously hyperintense. No secondary ducts dilatations were detected. During the follow-up, one patient presented disease recurrence 48months after surgery. MR imaging features can be highly suggestive for the diagnosis of SPN.

Pleomorphic solid pseudopapillary neoplasm of the pancreas: degenerative change rather than high-grade malignant potential

Solid pseudopapillary neoplasms (SPNs) are rare tumors of the pancreas characterized by poorly cohesive uniform cells with solid and pseudopapillary growth patterns. Nuclear pleomorphism is not a well-recognized feature of SPNs and may complicate differentiation from other pancreatic neoplasms. We compared histologic, immunohistochemical, and clinical features of 18 pleomorphic SPNs with 121 conventional SPNs. The prevalence of pleomorphic SPN was 12.9% (18/139). Pleomorphic SPNs arose in older patients (median, 45 years versus 32 years; P < .001), but no differences were found in sex, tumor location, recurrence, and metastasis when compared with conventional SPNs. Except for pleomorphic nuclei, other cytologic and histologic features of pleomorphic SPNs, such as growth pattern, tumor size, infiltrative pattern, tumor extension, mitosis, and Ki-67 labeling index, were not different from those of conventional SPNs. Pleomorphic SPNs showed a significantly higher p53 protein expression (64.7% [11/17 cases]) than that of conventional SPNs (1.8% [2/112 cases], P < .001). However, immunoreactivity for β-catenin and E-cadherin was not different between pleomorphic and conventional SPNs. A TP53 gene mutation was observed in 2 of 3 p53-immunoreactive pleomorphic SPNs. In summary, nuclear pleomorphism occurs in a subset of SPNs. They are more often p53 immunoreactive than SPNs without pleomorphism, and some harbor TP53 gene mutations. However, pleomorphic SPNs do not appear to be more aggressive than conventional SPNs. Low mitotic rate and Ki-67 labeling index may suggest nuclear pleomorphisms as degenerative changes. Recognition of typical poorly cohesive tumor cells and immunohistochemical features could establish the correct diagnosis of SPNs.