Comparison between solid pseudopapillary neoplasms of the pancreas and pancreatic ductal adenocarcinoma with cystic changes using computed tomography

BACKGROUND Solid pseudopapillary neoplasms of the pancreas(SPN)share similar imaging findings with pancreatic ductal adenocarcinoma with cystic changes(PDAC with cystic changes),which may result in unnecessary surgery.AIM To investigate the value of computed tomography(CT)in differentiation of SPN from PDAC with cystic changes.METHODS This study retrospectively analyzed the clinical and imaging findings of 32 patients diagnosed with SPN and 14 patients diagnosed with PDAC exhibiting cystic changes,confirmed through pathological diagnosis.Quantitative and qualitative analysis was performed,including assessment of age,sex,tumor size,shape,margin,density,enhancement pattern,CT values of tumors,CT contrast enhancement ratios,“floating cloud sign,”calcification,main pancreatic duct dilatation,pancreatic atrophy,and peripancreatic invasion or distal metastasis.Multivariate logistic regression analysis was used to identify relevant features to differentiate between SPN and PDAC with cystic changes,and receiver operating characteristic curves were obtained to evaluate the diagnostic performance of each variable and their combination.RESULTS When compared to PDAC with cystic changes,SPN had a lower age(32 years vs 64 years,P<0.05)and a slightly larger size(5.41 cm vs 3.90 cm,P<0.05).SPN had a higher frequency of“floating cloud sign”and peripancreatic invasion or distal metastasis than PDAC with cystic changes(both P<0.05).No significant difference was found with respect to sex,tumor location,shape,margin,density,main pancreatic duct dilatation,calcification,pancreatic atrophy,enhancement pattern,CT values of tumors,or CT contrast enhancement ratios between the two groups(all P>0.05).The area under the receiver operating characteristic curve of the combination was 0.833(95%confidence interval:0.708-0.957)with 78.6%sensitivity,81.3%specificity,and 80.4%accuracy in differentiation of SPN from PDAC with cystic changes.CONCLUSION A larger tumor size,“floating cloud sign,”and peripancreatic invasion or distal metastasis are useful CT imaging features that are more common in SPN and may help discriminate SPN from PDAC with cystic changes.

Solid pseudopapillary tumor of the pancreas:A systematic review of clinical,surgical and oncological characteristics of 1384 patients underwent pancreatic surgery

Background:Pancreatic solid pseudopapillary tumors(SPTs)are rare clinical entity,with low malignancy and still unclear pathogenesis.They account for less than 2%of exocrine pancreatic neoplasms.This study aimed to perform a systematic review of the main clinical,surgical and oncological characteristics of pancreatic SPTs.Data sources:MEDLINE/PubMed,Web of Science and Scopus databases were systematically searched for the main clinical,surgical and oncological characteristics of pancreatic SPTs up to April 2021,in accordance with the preferred reporting items for systematic reviews and meta-analyses(PRISMA)standards.Primary endpoints were to analyze treatments and oncological outcomes.Results:A total of 823 studies were recorded,86 studies underwent full-text reviews and 28 met inclusion criteria.Overall,1384 patients underwent pancreatic surgery.Mean age was 30 years and 1181 patients(85.3%)were female.The most common clinical presentation was non-specific abdominal pain(52.6%of cases).Mean overall survival was 98.1%.Mean recurrence rate was 2.8%.Mean follow-up was 4.2 years.Conclusions:Pancreatic SPTs are rare,and predominantly affect young women with unclear pathogenesis.Radical resection is the gold standard of treatment achieving good oncological impact and a favorable prognosis in a yearly life-long follow-up.

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

BACKGROUND 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.AIM To determine the characteristic EUS features of SPN and define its role in preoperative assessment.METHODS 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.RESULTS 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.CONCLUSION 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.

Extrapancreatic solid pseudopapillary neoplasm followed by multiple metastases:Case report

Solid pseudopapillary neoplasm(SPN), also known as Gruber-Frantz tumor, is a rare form of neoplasm that almost exclusively occurs in the pancreas and in young females. While the potential of malignancy is low for SPN, these tumors can mimic other diseases and require a meticulous investigation and a standard treatment by total surgical resection. We present an unusual case of SPN arising in the mesentery of a 40-year-old man with subsequent multiple metastases. Histopathological examination showed similar properties of the mesenteric neoplasm to those of SPN in pancreas. Although the mass was surgically removed, the patient died of recurrent disease 4 years after the initial presentation. We speculate that SPN originates from pancreatic progenitor cells. Further histopathological analyses are required for the prediction of SPN recurrence after resection.

Transarterial chemoembolization for liver metastases from solid pseudopapillary epithelial neoplasm of pancreas: A case report

Solid pseudo-papillary epithelial neoplasm(SPEN) is a rare epithelial tumor of pancreas with a low malignant potential occurs most commonly in young females. We report a case of 40 years old woman presented withextensive liver metastasis from SPEN of pancreatic body for which she was operated four years ago. Due to the extensive nature of metastatic disease she was offered Transarterial chemoembolisation(TACE) using gemcitabine as chemotherapeutic agent. Short term follow up after a month of TACE with multiphase computed tomography showed > 90% resolution in the viable tumor with significant clinical improvement. TACE ensures targeted delivery of chemotherapeutic drugs in higher doses with least systemic toxicity and is more effective and safe than systemic chemotherapy. TACE with gemcitabine was found to be very effective in our patient with numerous liver metastasis.

Synchronous pancreatic solid pseudopapillary neoplasm and intraductal papillary mucinous neoplasm

Solid pseudopapillary neoplasm (SPN) is a rare and low-grade malignant pancreatic neoplasm composed of poorly cohesive monomorphic neoplastic cells forming solid and pseudopapillary structures with frequent hemorrhagic-cystic degeneration. Intraductal papillary mucinous neoplasm (IPMN) is a pancreatic exocrine tumor composed of intraductal papillary growth of mucin containing neoplastic cells in the main pancreatic duct or its major branches. In the case presented here, a 53-year-old, Japanese man was found to have multiple cystic lesions and dilatation of the main pancreatic duct in the neck of the pancreas. Histological examination revealed a main-duct and branch-duct type IPMN, of the gastric-type, involving the neck of the pancreas, associated with a 0.5 cm SPN in the caudal side of the IPMN. We diagnosed this case as synchronous SPN and IPMN. As far as we know, only one other case of synchronous SPN and IPMN has been reported. Both the present case and the previously reported case showed abnormal nuclear expression of β-catenin in SPN, whereas IPMN showed no abnormal nuclear expression. These results suggest that β-catenin abnormality is not a common pathogenetic factor of synchronous SPN and IPMN.

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 cytoplasmicβ-catenin.Almost all solid pseudopapillary neoplasms harbour mutations in exon 3 of CTNNB1,the gene encodingβ-catenin.The overall prognosis is excellent,and most patients are cured by complete surgical resection.

Prospects and applications of enucleation in solid pseudopapillary neoplasms of the pancreas

Solid pseudopapillary neoplasms(SPNs)of the pancreas are rare,low-grade,malignant neoplasms that are mostly seen in young women in the second and third decades of life and are quite uncommon in children.Standard resection for benign and borderline neoplasms of the pancreas is associated with a substantial risk of postoperative morbidity and long-term functional impairment,whereas enucleation leads to less morbidity and preserves healthy parenchyma as well as exocrine and endocrine function.Enucleation of SPNs has been increasingly reported to be feasible and safe for preserving the normal physiological function of the pancreas,especially in teenagers and children.This review summarizes findings published in recent years on the enucleation of SPNs as well as potential future developments and directions.Enucleation has undoubtedly come to stay as an alternative surgical procedure for SPNs.However,many questions remain unresolved,and future directions toward the best surgical indication,the prevention and intervention of complications,especially pancreatic fistula,intraoperative resection margin safety assessment,and long-term oncology prognosis remain to be evaluated and should be explored in future clinical trials.

Mismatch repair proteins and microsatellite instability in solid pseudopapillary neoplasm of the pancreas

Solid pseudopapillary neoplasms (SPNs) are rare solid pancreatic tumors mainly affecting young women. Despite the high percentage of favorable prognosis, they are considered as low grade malignant neoplasms, and metastases occur in 5%-15% of patients. Almost all SPNs (95%) have somatic activating mutations in the β-catenin gene [1].

Pathological differential diagnosis of solid-pseudopapillary neoplasm and endocrine tumors of the pancreas

AIM:To investigate differential points of solid-pseudo-papillary neoplasm (SPN) of the pancreas and pancre-atic endocrine tumor (PET).METHODS:Ten cases of SPN and fourteen cases of PET were studied in this retrospective study. Clinical and pathologic features,immunostaining reactions and β-catenin gene mutations were analyzed.RESULTS:The mean age of SPN patients was 25.6 years and these patients had no specific symptoms. The mean diameter of the tumors was 11.0 cm,9/10 cases were cystic or a mixture of solid and cystic structures,and there was hemorrhage and necrosis on the cut surface in 8/10 (80%) cases. Characteristic pseudo-papillary structure and discohesive appearance of the neoplastic cells were observed in all 10 (100%) cases. The results of immunostaining showed that nuclear expression of β-catenin and loss of E-cadherin in all the cases,was only seen in SPN. Molecular studies discov-ered that 9/10 (90%) cases harbored a point mutation of exon 3 in β-catenin gene. On the other hand,the mean age of PET patients was 43.1 years. Eight of 14 cases presented with symptoms caused by hypoglyce-mia,and the other 6 cases presented with symptoms similar to those of SPN. The mean size of the tumors was 2.9 cm,most of the tumors were solid,only 3/14 (21%) were a mixture of solid and cystic structures,and macroscopic hemorrhage and necrosis were much less common (3/14,21%). Histologically,tumor cells were arranged in trabecular,acinar or solid patterns and demonstrated no pseudopapillary structure and discohesive appearance in all 14 (100%) cases. The results of immunostaining and mutation detection were completely different with SPN that membrane and cytoplastic expression of β-catenin without loss of E-cadherin,as well as no mutation in β-catenin gene in all the cases. CONCLUSION:Both macroscopic and microscopic features of SPN are quite characteristic. It is not difficult to distinguish it from PET. If necessary,immunos-taining of β-catenin and E-cadherin is quite helpful to make the differential diagnosis.

Impact of parenchyma-preserving surgical methods on treating patients with solid pseudopapillary neoplasms:A retrospective study with a large sample size

BACKGROUND Solid pseudopapillary neoplasm of the pancreas(SPN)is a rare neoplasm that mainly affects young women.AIM To evaluate the impact of parenchyma-preserving surgical methods(PPMs,including enucleation and central pancreatectomy)in the treatment of SPN patients.METHODS From 2013 to 2019,patients who underwent pancreatectomy for SPNs were retrospectively reviewed.The baseline characteristics,intraoperative index,pathological outcomes,short-term complications and long-term follow-up data were compared between the PPM group and the conventional method(CM)group.RESULTS In total,166 patients were included in this study.Of them,33 patients(19.9%)underwent PPM.Most of the tumors(104/166,62.7%)were found accidentally.Comparing the parameters between groups,the hospital stay d(12.35 vs 13.5 d,P=0.49),total expense(44213 vs 54084 yuan,P=0.21),operation duration(135 vs 120 min,P=0.71),and intraoperative bleeding volume(200 vs 100 mL,P=0.49)did not differ between groups.Regarding pathological outcomes,tumor size(45 vs 32 mm,P=0.07),Ki67 index(P=0.53),peripheral tissue invasion(11.3%vs 9.1%,P=0.43)and positive margin status(7.5%vs 6%,P=0.28)also did not differ between groups.Moreover,PPM did not increase the risk of severe postoperative pancreatic fistula(3.8%vs 3.0%,P=0.85)or tumor recurrence(3.0%vs 6.0%,P=0.39).However,the number of patients who had exocrine insufficiency during follow-up was significantly lower in the PPM group(21.8%vs 3%,P=0.024).CM was identified as an independent risk factor for pancreatic exocrine insufficiency(odds ratio=8.195,95%confident interval:1.067-62.93).CONCLUSION PPM for SPN appears to be feasible and safe for preserving the exocrine function of the pancreas.

SMARCB1/INI1-deficient pancreatic undifferentiated rhabdoid carcinoma mimicking solid pseudopapillary neoplasm: A case report and review of the literature

BACKGROUND SMARCB1/INI1-deficient pancreatic undifferentiated rhabdoid carcinoma is a very aggressive tumor that is rarely reported in the literature.The tumor has a predominant rhabdoid cell component and different patterns of growth have been reported.CASE SUMMARY A 59-year-old woman presented with diffuse abdominal pain,increasing in severity and accompanied by weight loss,nausea,and vomiting.Imaging showed a pancreatic head mass.Fine needle aspiration demonstrated atypical epithelioid cells with a pseudopapillary growth pattern suggestive of solid pseudopapillary neoplasm.The excised neoplasm showed monotonous epithelioid and focally spindle cells with pseudopapillary structures,rhabdoid features,and loss of SMARCB1 protein expression with wild-type KRAS,consistent with a SMARCB1/INI1-deficient undifferentiated rhabdoid carcinoma.The patient’s condition deteriorated rapidly following surgery and she expired 3 mo post operation.CONCLUSION In this article,we report the first case of SMARCB1/INI1-deficient undifferentiated pancreatic rhabdoid carcinoma mimicking solid pseudopapillary neoplasm.

Solid pseudopapillary neoplasm-diagnostic approach and postsurgical follow up:Three case reports and review of literature

BACKGROUND Solid pseudopapillary neoplasm(SPN)is a rare tumor that was first described by Frantz in 1959.Although this tumor is benign,some may have malignant potential that can be predicted based on demographics,imaging characteristics,and pathologic evaluation.This case series presents 3 SPN cases with discussion on gender differences,preoperative predictors of malignancy,and a suggested algorithm for diagnostic approach as well as post-surgical follow up.CASE SUMMARY Three adult patients in a tertiary hospital found to have SPN,one elderly male and two young females.Each of the cases presented with abdominal pain and were discovered incidentally.Two cases underwent endoscopic ultrasound with immunohistochemical staining(which were consistent with SPN before undergoing surgery),and one case underwent surgery directly after imaging.The average tumor size was 5 cm.Diagnosis was confirmed by histology.Two patients had post-surgical complications requiring intervention.CONCLUSION Demographic and imaging characteristics can be sufficient to establish diagnosis for SPN,while malignant cases require pre-operative evaluation with endoscopic ultrasound fine needle aspiration/fine needle biopsy.

Solid pseudopapillary neoplasm of the pancreas in a young male with main pancreatic duct dilatation: A case report

BACKGROUND Solid pseudopapillary neoplasms(SPNs)are rare tumors of the pancreas.Typically,they occur in young females,often have characteristic imaging features,such as cystic components and calcification,and have few effects on the pancreatic duct.CASE SUMMARY A 31-year-old man was admitted to our hospital with the chief complaint of epigastric pain.There was only mild tenderness in his upper abdomen,and blood tests showed only a slight increase in alkaline phosphatase.Contrast-enhanced computed tomography showed a 40-mm-diameter,hypovascular mass in the head of the pancreas,and the main pancreatic duct upstream of the mass was severely dilated.Magnetic resonance imaging showed low intensity on T1-weighted images,with high intensity on T2-weighted image in some parts.Pancreatic ductal adenocarcinoma was the primary differential diagnosis.Portal vein infiltration could not be ruled out,so this case was a candidate for neoadjuvant chemotherapy.Subsequently,endoscopic ultrasound-guided fine needle aspiration was performed,and pathological evaluation and immunostaining suggested a diagnosis of SPN.Thus,pancreatoduodenectomy was performed.One year after the operation,the patient is alive with no recurrence.CONCLUSION Main pancreatic duct dilatation is usually a finding of suspected pancreatic cancer.However,pancreatic duct dilatation can occur in SPN depending on the location and growth speed.Therefore,SPN should be considered in the differential diagnosis of tumors with pancreatic duct dilatation,and pathological evaluation by endoscopic ultrasound-guided fine needle aspiration should be actively performed.

Solid pseudopapillary tumor of the pancreas:A review of 553 cases in Chinese literature

AIM:To sum up the clinical and pathological characte- ristics of solid pseudopapillary tumor (SPT) and the experience with it.METHODS: A total of 553 SPT patients reported in Chinese literature between January 1996 and January 2009 were retrospectively reviewed and analyzed. RESULTS: The mean age of the 553 SPT patients included in this review was 27.2 years, and the male to female ratio was 1:8.37. Their symptoms were non-specific, and nearly one third of the patients were asymptomatic. Computed tomography and ultraso-nography were performed to show the nature and location of SPT. Most of the tumors were distributed in the pancreatic head (39.8%), tail (24.1%), body andtail (19.5%). Forty-five patients (9.2%) were diagnosed as malignant SPT with metastasis or invasion. None of the clinical factors was closely related to the malignant potential of SPT. Surgery was the main therapeutic modality for SPT. Local resection, distal pancreatectomy and pancreatoduodenectomy were the most common surgical procedures. Local recurrence and hepatic metastasis were found in 11 and 2 patients, respectively, after radical resection. Four patients died of tumor progression within 4 years after palliative resection of SPT. The prognosis of SPT patients was good with a 5-year survival rate of 96.9%.CONCLUSION: SPT of the pancreas is a rare indolent neoplasm that typically occurs in young females. It is a low-grade malignancy and can be cured with extended resection. The prognosis of such patients is good although the tumor may recur and metastasize.

Solid pseudopapillary tumor of the pancreas in male patients: Report of 16 cases

AIM: To investigate the clinical characteristics, surgical strategies and prognosis of solid pseudopapillary tumors (SPTs) of the pancreas in male patients. METHODS: From July 2003 to March 2013, 116 patients were diagnosed with SPT of the pancreas in our institution. Of these patients, 16 were male. The patients were divided into two groups based on gender: female (group 1) and male (group 2). The groups were compared with regard to demographic characteristics, clinical presentations, surgical strategies, complications and follow-up outcomes. RESULTS: Male patients were older than female patients (43.1 +/- 12.3 years vs 33.1 +/- 11.5 years, P = 0.04). Tumor size, location, and symptoms were comparable between the two groups. All patients, with the exception of one, underwent complete surgical resection. The patients were regularly followed up. The mean follow-up period was 58 mo. Two female patients (1.7%) developed tumor recurrence or metastases and required a second resection, and two female patients (1.7%) died during the follow-up period. CONCLUSION: Male patients with SPT of the pancreas are older than female patients. There are no significant differences between male and female patients regarding surgical strategies and prognosis. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Clinical analysis of solid-pseudopapillary tumor of the pancreas:report of 15 cases

BACKGROUND: Solid-pseudopapillary tumor of the pancreas (SPTP) is an uncommon and enigmatic pancreatic neoplasm that occurs mainly in young women. Although more and more cases have been reported in recent years, misdiagnosis and incorrect treatment still frequently take place. This study was designed to stimulate consideration of this tumor. METHODS: We retrospectively reviewed the experience of diagnosis and treatment of 15 patients with SPTP and compared them with 516 patients with pancreatic cancer from January 1997 to March 2007. RESULTS: Most of the SPTP cases were asymptomatic except for one palpable mass. Almost all SPTPs demonstrated a solid structure with hypo- or isoattenuation, cystic structure with hypo-attenuation on precontrast CT scan, and enhancement of solid portions on post-contrast CT scan. By contrast, most cases of pancreatic carcinoma had multiple symptoms and abnormal blood results. The tumors showed hypo-attenuation on both precontrast and post-contrast CT scan, and only a few showed iso-attenuation on post-contrast CT scan. All cases of SPTP in our group were cured by surgical resection, while only 16.86% of patients with pancreatic carcinoma could undergo a radical resection. CONCLUSIONS: Clinical features and CT scans were helpful to differentiate SPTP from pancreatic carcinoma. Radical surgical resection was the most effective and safe method for the treatment of SPTP.

Analysis of invasiveness and tumor-associated macrophages infiltration in solid pseudopapillary tumors of pancreas

BACKGROUND Solid pseudopapillary tumor(SPT)is a rare pancreatic tumor.Considering its malignant behaviors,SPT has been classified as a low-grade malignant tumor.Indeed,only 9.2%of all SPT patients are initially diagnosed as malignant with invasion or metastasis.Thus,one of the challenges in managing SPT patients is predicting malignant behavior.AIM To investigate the malignant behavior and tumor-associated macrophage(TAM)infiltration between different histopathologic features of SPT patients.METHODS Twenty-five formalin-fixed paraffin-embedded tissue samples from 22 patients pathologically diagnosed with an SPT between 2009 and 2019 at West China Hospital were included in this retrospective study.Integrity of the capsule and growth pattern of the tumor cells was assessed microscopically in hematoxylineosin(HE)-stained sections.Based on the histopathological features,the SPT patients were divided into two groups:capsule or invasion.Clinical features,malignant behavior,and TAM infiltration were compared between the two groups.RESULTS Among the 22 SPT patients,11 were identified for each group,having either a capsule or invasion histopathologic feature.Malignant behavior was more frequent in the invasion group,including 2 patients who had peripheral organ invasion,3 with liver metastasis,and 1 with both lymph node and spleen metastases(P=0.045).Ki-67 index of more than 3%was also more frequent in the invasion group(P=0.045).Immunohistochemical analysis showed that the invasion group had a significant increase of CD68-positive TAMs in intratumor and peritumor sites in comparison with the capsule group(all P<0.0001).Similarly,CD163-positive M2-like macrophages were also markedly increased in the intratumor and peritumor sites in the invasion group(all P<0.0001).At the liver metastasis site,both intratumor and peritumor tissues showed relatively high-level CD68-positive TAMs and CD163-positive M2-like macrophages infiltration.However,the differences between the intratumor,peritumor and normal hepatic tissues did not reach statistical significance(all P>0.05).CONCLUSION SPT patients with invasion evident under microscope were more likely to exhibit malignant behavior and TAM infiltration,especially M2-like macrophages.This finding can help in future investigations of the underlying mechanism of TAM-mediated SPT malignant behavior.

The clinicopathological and immuohistochemical analysis of solid-pseudopapillary tumor of the pancreas:report of 9 cases

Objective：To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas（SPTP）. Methods：Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin（HE） staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results：Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin（9/9 cases）, AAT（9/9 cases）, NSE（9/9 cases）, ACT（7/9 cases）, CK20（2/9 cases）, CgA（1/9 cases）, S-100（3/gcases）, PR（4/gcases）, Syn（3/9 cases） and CD56（5/9cases）, negative in CEA and ER. Conclusion：SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.

Treatment of aggressive pancreatic solid pseudo-papillary neoplasms with apatinib plus S-1 chemotherapy:A case report and literature review

Solid pseudopapillary neoplasm(SPN) is a rare indolent pancreatic neoplasm that occurs mostly in females. Although the malignancy potential is quite limited for SPN, these tumors can sometimes be aggressive and lead to inferior prognosis for male patients. In this case report, we present a special case of a male patient with SPN who experienced an aggressive tumor expansion after two surgical resections. For further treatment, we decided to administer chemotherapy with apatinib and S-1, and subsequent CT/MRI tumor monitoring indicated satisfactory control of tumor expansion. The effectiveness of apatinib plus the S-1 regimen should be tested for more patients with SPN in the future.