A Dynamic Multi-Scale Convolution Model for Face Recognition Using Event-Related Potentials.

With the development of data mining technology, the analysis of event-related potential (ERP) data has evolved from statistical analysis of time-domain features to data-driven techniques based on supervised and unsupervised learning. However, there are still many challenges in understanding the relationship between ERP components and the representation of familiar and unfamiliar faces. To address this, this paper proposes a model based on Dynamic Multi-Scale Convolution for group recognition of familiar and unfamiliar faces. This approach uses generated weight masks for cross-subject familiar/unfamiliar face recognition using a multi-scale model. The model employs a variable-length filter generator to dynamically determine the optimal filter length for time-series samples, thereby capturing features at different time scales. Comparative experiments are conducted to evaluate the model's performance against SOTA models. The results demonstrate that our model achieves impressive outcomes, with a balanced accuracy rate of 93.20% and an F1 score of 88.54%, outperforming the methods used for comparison. The ERP data extracted from different time regions in the model can also provide data-driven technical support for research based on the representation of different ERP components.

SpaRx: elucidate single-cell spatial heterogeneity of drug responses for personalized treatment.

Spatial cellular authors heterogeneity contributes to differential drug responses in a tumor lesion and potential therapeutic resistance. Recent emerging spatial technologies such as CosMx, MERSCOPE and Xenium delineate the spatial gene expression patterns at the single cell resolution. This provides unprecedented opportunities to identify spatially localized cellular resistance and to optimize the treatment for individual patients. In this work, we present a graph-based domain adaptation model, SpaRx, to reveal the heterogeneity of spatial cellular response to drugs. SpaRx transfers the knowledge from pharmacogenomics profiles to single-cell spatial transcriptomics data, through hybrid learning with dynamic adversarial adaption. Comprehensive benchmarking demonstrates the superior and robust performance of SpaRx at different dropout rates, noise levels and transcriptomics coverage. Further application of SpaRx to the state-of-the-art single-cell spatial transcriptomics data reveals that tumor cells in different locations of a tumor lesion present heterogenous sensitivity or resistance to drugs. Moreover, resistant tumor cells interact with themselves or the surrounding constituents to form an ecosystem for drug resistance. Collectively, SpaRx characterizes the spatial therapeutic variability, unveils the molecular mechanisms underpinning drug resistance and identifies personalized drug targets and effective drug combinations.

SiGra: single-cell spatial elucidation through an image-augmented graph transformer.

Recent advances in high-throughput molecular imaging have pushed spatial transcriptomics technologies to subcellular resolution, which surpasses the limitations of both single-cell RNA-seq and array-based spatial profiling. The multichannel immunohistochemistry images in such data provide rich information on the cell types, functions, and morphologies of cellular compartments. In this work, we developed a method, single-cell spatial elucidation through image-augmented Graph transformer (SiGra), to leverage such imaging information for revealing spatial domains and enhancing substantially sparse and noisy transcriptomics data. SiGra applies hybrid graph transformers over a single-cell spatial graph. SiGra outperforms state-of-the-art methods on both single-cell and spot-level spatial transcriptomics data from complex tissues. The inclusion of immunohistochemistry images improves the model performance by 37% (95% CI: 27-50%). SiGra improves the characterization of intratumor heterogeneity and intercellular communication and recovers the known microscopic anatomy. Overall, SiGra effectively integrates different spatial modality data to gain deep insights into spatial cellular ecosystems.

SpaRx: Elucidate single-cell spatial heterogeneity of drug responses for personalized treatment.

Spatial cellular heterogeneity contributes to differential drug responses in a tumor lesion and potential therapeutic resistance. Recent emerging spatial technologies such as CosMx SMI, MERSCOPE, and Xenium delineate the spatial gene expression patterns at the single cell resolution. This provides unprecedented opportunities to identify spatially localized cellular resistance and to optimize the treatment for individual patients. In this work, we present a graph-based domain adaptation model, SpaRx, to reveal the heterogeneity of spatial cellular response to drugs. SpaRx transfers the knowledge from pharmacogenomics profiles to single-cell spatial transcriptomics data, through hybrid learning with dynamic adversarial adaption. Comprehensive benchmarking demonstrates the superior and robust performance of SpaRx at different dropout rates, noise levels, and transcriptomics coverage. Further application of SpaRx to the state-of-art single-cell spatial transcriptomics data reveals that tumor cells in different locations of a tumor lesion present heterogenous sensitivity or resistance to drugs. Moreover, resistant tumor cells interact with themselves or the surrounding constituents to form an ecosystem for drug resistance. Collectively, SpaRx characterizes the spatial therapeutic variability, unveils the molecular mechanisms underpinning drug resistance, and identifies personalized drug targets and effective drug combinations. Key Points: We have developed a novel graph-based domain adaption model named SpaRx, to reveal the heterogeneity of spatial cellular response to different types of drugs, which bridges the gap between pharmacogenomics knowledgebase and single-cell spatial transcriptomics data.SpaRx is developed tailored for single-cell spatial transcriptomics data and is provided available as a ready-to-use open-source software, which demonstrates high accuracy and robust performance.SpaRx uncovers that tumor cells located in different areas within tumor lesion exhibit varying levels of sensitivity or resistance to drugs. Moreover, SpaRx reveals that tumor cells interact with themselves and the surrounding microenvironment to form an ecosystem capable of drug resistance.

spaCI: deciphering spatial cellular communications through adaptive graph model.

Cell-cell communications are vital for biological signalling and play important roles in complex diseases. Recent advances in single-cell spatial transcriptomics (SCST) technologies allow examining the spatial cell communication landscapes and hold the promise for disentangling the complex ligand-receptor (L-R) interactions across cells. However, due to frequent dropout events and noisy signals in SCST data, it is challenging and lack of effective and tailored methods to accurately infer cellular communications. Herein, to decipher the cell-to-cell communications from SCST profiles, we propose a novel adaptive graph model with attention mechanisms named spaCI. spaCI incorporates both spatial locations and gene expression profiles of cells to identify the active L-R signalling axis across neighbouring cells. Through benchmarking with currently available methods, spaCI shows superior performance on both simulation data and real SCST datasets. Furthermore, spaCI is able to identify the upstream transcriptional factors mediating the active L-R interactions. For biological insights, we have applied spaCI to the seqFISH+ data of mouse cortex and the NanoString CosMx Spatial Molecular Imager (SMI) data of non-small cell lung cancer samples. spaCI reveals the hidden L-R interactions from the sparse seqFISH+ data, meanwhile identifies the inconspicuous L-R interactions including THBS1-ITGB1 between fibroblast and tumours in NanoString CosMx SMI data. spaCI further reveals that SMAD3 plays an important role in regulating the crosstalk between fibroblasts and tumours, which contributes to the prognosis of lung cancer patients. Collectively, spaCI addresses the challenges in interrogating SCST data for gaining insights into the underlying cellular communications, thus facilitates the discoveries of disease mechanisms, effective biomarkers and therapeutic targets.

Feature Selection for Unsupervised Machine Learning.

Compared to supervised machine learning (ML), the development of feature selection for unsupervised ML is far behind. To address this issue, the current research proposes a stepwise feature selection approach for clustering methods with a specification to the Gaussian mixture model (GMM) and the k-means. Rather than the existing GMM and k-means which are carried out based on all the features, the proposed method selects a subset of features to implement the two methods, respectively. The research finds that a better result can be obtained if the existing GMM and k-means methods are modified by nice initializations. Experiments based on Monte Carlo simulations show that the proposed method is more computationally efficient and the result is more accurate than the existing GMM and k-means methods based on all the features. The experiment based on a real-world dataset confirms this finding.

PINet: Privileged Information Improve the Interpretablity and generalization of structural MRI in Alzheimer's Disease.

The irreversible and progressive atrophy by Alzheimer's Disease resulted in continuous decline in thinking and behavioral skills. To date, CNN classifiers were widely applied to assist the early diagnosis of AD and its associated abnormal structures. However, most existing black-box CNN classifiers relied heavily on the limited MRI scans, and used little domain knowledge from the previous clinical findings. In this study, we proposed a framework, named as PINet, to consider the previous domain knowledge as a Privileged Information (PI), and open the black-box in the prediction process. The input domain knowledge guides the neural network to learn representative features and introduced intepretability for further analysis. PINet used a Transformer-like fusion module Privileged Information Fusion (PIF) to iteratively calculate the correlation of the features between image features and PI features, and project the features into a latent space for classification. The Pyramid Feature Visualization (PFV) module served as a verification to highlight the significant features on the input images. PINet was suitable for neuro-imaging tasks and we demonstrated its application in Alzheimer's Disease using structural MRI scans from ADNI dataset. During the experiments, we employed the abnormal brain structures such as the Hippocampus as the PI, trained the model with the data from 1.5T scanners and tested from 3T scanners. The F1-score showed that PINet was more robust in transferring to a new dataset, with approximatedly 2% drop (from 0.9471 to 0.9231), while the baseline CNN methods had a 29% drop (from 0.8679 to 0.6154). The performance of PINet was relied on the selection of the domain knowledge as the PI. Our best model was trained under the guidance of 12 selected ROIs, major in the structures of Temporal Lobe and Occipital Lobe. In summary, PINet considered the domain knowledge as the PI to train the CNN model, and the selected PI introduced both interpretability and generalization ability to the black box CNN classifiers.

Generalized k -means in GLMs with applications to the outbreak of COVID-19 in the United States.

Generalized k -means can be combined with any similarity or dissimilarity measure for clustering. Using the well known likelihood ratio or F -statistic as the dissimilarity measure, a generalized k -means method is proposed to group generalized linear models (GLMs) for exponential family distributions. Given the number of clusters k , the proposed method is established by the uniform most powerful unbiased (UMPU) test statistic for the comparison between GLMs. If k is unknown, then the proposed method can be combined with generalized liformation criterion (GIC) to automatically select the best k for clustering. Both AIC and BIC are investigated as special cases of GIC. Theoretical and simulation results show that the number of clusters can be correctly identified by BIC but not AIC. The proposed method is applied to the state-level daily COVID-19 data in the United States, and it identifies 6 clusters. A further study shows that the models between clusters are significantly different from each other, which confirms the result with 6 clusters.

The complete mitochondrial genomes of Parabotia kiangsiensis (Cypriniformes: Botiidae).

Parabotia kiangsiensis is an endemic species of genus Parabotia in China. In this study, we sequenced the complete mito-genome of P. kiangsiensis. The genome is 16,592 base pair (bp) in length, encoding 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one non-coding control region (D-loop). The nucleotide composition is A: 30.66%, T: 25.13%, G: 16.3%, and C: 27.92% (AT content:55.79%). The complete mitogenome of P. kiangsiensis provides basic data for the genetic diversity conservation of this species.

[Surgical experience on Roux-en-Y pancreaticojejunostomy after local pancreatic head resection for benign tumors of the pancreatic head].

OBJECTIVE: To explore the value of Roux-en-Y pancreaticojejunostomy after local pancreatic head resection in treating benign tumors of pancreatic head (BTPH). METHODS: The clinical data of 12 patients diagnosed as BTPH and treated by Roux-en-Y pancreaticojejunostomy after local pancreatic head resection in Department of General Surgery, Peking University Third Hospital from November 2006 to October 2013 were retrospectively analyzed.Of the 12 cases, 5 patients were male, 7 patients were female, the age of patients ranged from 21 to 64 years(average 42.3 years). Diameter of tumors was 3.0-4.8 cm.Diameter of pancreatic wound after resection was 5.1-7.9 cm, and main pancreatic duct injury happened in 1 case. RESULTS: Two cases of mucinous cystadenoma, 2 insulinoma, 3 solid pseudopapillary tumor and 4 nonfunctional pancreatic neuroendocrine tumors were confirmed histopathologically.No mortality and pancreatic leakage occurred during the perioperative period.All the 12 patients had no sign of recurrence.Experienced good life quality without occurrence of diabetes during the follow-up period of 24-108 months(more than 60 months in 4 cases). CONCLUSIONS: Roux-en-Y pancreaticojejunostomy after local pancreatic head resection is a reasonable choice for benign tumors of the pancreatic head as long as the patient is properly selected.

Meta-analysis of Liver Resection Versus Nonsurgical Treatments for Pancreatic Neuroendocrine Tumors with Liver Metastases.

PURPOSE: Studies have reported limited evidence of the benefits and harms of various regimens, such as liver resection and medical therapy, for the treatment of pancreatic neuroendocrine tumors (pNETs) with liver metastases. This meta-analysis aimed to evaluate the efficacy of liver resection versus nonsurgical treatments in patients with pNET. METHODS: Relevant studies published in English were retrieved from the computerized databases Medline, Embase, and Cochrane. A meta-analysis was performed to investigate the differences in the efficacy of liver resection and nonsurgical treatments based on the evaluation of 30-day mortality, symptom relief rate, median survival time, and 2-, 3-, or 5-year survival using a random-effects model. Studies were independently reviewed by two investigators. Data from eligible studies were extracted, and the meta-analysis was performed using the comprehensive meta-analysis program version 2. RESULTS: A total of seven studies were included in the analysis. The results demonstrated that liver resection was significantly associated with a higher rate of symptom relief, longer median survival time, higher 2- or 3-year survival rates, as well as a higher 5-year survival rate. There was no significant difference in 30-day mortality among patients with pNETs who were treated by liver resection and nonsurgical therapy or survival between functional and nonfunctional pNETs. No publication bias was detected. CONCLUSIONS: Liver resection has a favorable prognostic outcome in terms of higher postoperative symptom relief rates and longer survival rates. Further randomized, controlled trials with longer follow-up periods are required to confirm the advantages of liver resection for pNETs.

Agriculture intensifies soil moisture decline in Northern China.

Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983-2012, we find that topsoil (0-50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of -0.011 to -0.015 m(3) m(-3) per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.

Duodenum-preserving resection and Roux-en-Y pancreatic jejunostomy in benign pancreatic head tumors.

This study was conducted to explore the feasibility of partial pancreatic head resection and Roux-en-Y pancreatic jejunostomy for the treatment of benign tumors of the pancreatic head (BTPH). From November 2006 to February 2009, four patients (three female and one male) with a mean age of 34.3 years (range: 21-48 years) underwent partial pancreatic head resection and Roux-en-Y pancreatic jejunostomy for the treatment of BTPH (diameters of 3.2-4.5 cm) using small incisions (5.1-7.2 cm). Preoperative symptoms include one case of repeated upper abdominal pain, one case of drowsiness and two cases with no obvious preoperative symptoms. All four surgeries were successfully performed. The mean operative time was 196.8 min (range 165-226 min), and average blood loss was 138.0 mL (range: 82-210 mL). The mean postoperative hospital stay was 7.5 d (range: 7-8 d). In one case, the main pancreatic duct was injured. Pathological examination confirmed that one patient suffered from mucinous cystadenoma, one exhibited insulinoma, and two patients had solid-pseudopapillary neoplasms. There were no deaths or complications observed during the perioperative period. All patients had no signs of recurrence of the BTPH within a follow-up period of 48-76 mo and had good quality of life without diabetes. Partial pancreatic head resection with Roux-en-Y pancreatic jejunostomy is feasible in selected patients with BTPH.

Data analysis of 36 cases with intraductal papillary mucinous neoplasm of the pancreas for their clinicopathological features, diagnosis, and treatment.

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) is a rare pancreatic cystic neoplasm, accounting for 1% of all exocrine pancreatic neoplasms. This study aimed to summarize the clinicopathological and biological behaviors, as well as the experience in diagnosis and treatment of IPMN. METHODS: Clinicopathological data were collected from 36 cases with IPMN who were treated in Department of General Surgery, Peking University Third Hospital from May 2001 to July 2011. RESULTS: The 36 cases of IPMN patients included 27 males and 9 females (M:F = 3:1). The age of patients ranged from 52 to 78 years, with an average of 67.3 years. Regarding tumor location, 20 tumors were located in pancreatic head, 3 in pancreatic neck, 10 in pancreatic body and tail, and 3 in the whole pancreas. All the 36 cases underwent surgical treatment, with 13 cases of pancreaticoduodenectomy, 3 cases of middle pancreatectomy, 7 cases of tumor resection plus pancreaticojejunostomy, 3 cases of distal pancreatectomy, 7 cases of distal pancreatectomy plus spleen resection, and 3 cases of total pancreaticoduodenectomy. Of the 36 patients, 9 patients underwent the operations under laparoscopy. The 36 cases included main duct type (14 cases, 38.9%), branch duct type (10 cases, 27.7%), and mixed duct type (12 cases, 33.3%). Pathologically, of the 36 cases, there were 7 IPMN adenomas, 11 borderline IPMNs, 6 IPMN with carcinomas in situ, and 12 IPMNs with invasive carcinomas. All the 36 cases were followed up. During an average of 42 months follow-up period (26-129 months), no recurrence occurred. CONCLUSIONS: IPMN, which primarily occurs in male, is a low-grade malignancy which may involve any part of the pancreas, with specific clinicopathological features. IPMN is a different malignancy type from pancreatic ductal carcinoma. Imaging and laboratory examination are helpful for the diagnosis and differential diagnosis. The prediction of invasive IPMN is still difficult. Surgical resection is recommended as the first choice of treatment. Aggressive and proper operation procedure produces better prognosis. Long-term follow-up is necessary for patients after operation. Laparoscopic distal pancreatectomy is a feasible and safe procedure for the indicated patients.

[Ultrasound guided ablation therapy of hepatic colorectal metastases: initial experience of real time virtual sonography navigation system].

OBJECTIVE: To evaluate the feasibility, accuracy and efficacy of the real time virtual sonography navigation and planning system in radio frequency ablation (RFA) of hepatic colorectal metastases. METHODS: Seventeen hepatic colorectal metastases lesions in 12 patients diagnosed pathologically or clinically in Peking University Third Hospital from Oct. 2011 to Apr. 2013 were enrolled, and all the lesions were diagnosed by CT/MRI but invisible in B-mode ultrasound. The patients included 9 males and 3 females, who were 45-82 years old, with an average age of (64.6±19.2) years. Before RFA, the puncture ablation plan of each lesion was made in the planning system, and during RFA the lesion and the 5 mm ablative margin around were ablated according to the puncture ablation plan. After the image fusion between the ultrasound and CT/MRI, the navigation system could decide the location and boundary of the hepatic colorectal metastases in the ultrasound image. Navigation assisted contrast-enhanced ultrasound (CEUS) was employed right after ablation to decide whether the area of the ablative zone had covered the whole tumor. Additional puncture was applied if the ablative zone had not completely covered the tumor. All the patients received CT/MRI one month after ablation to decide whether the carcinoma had been completely ablated. RESULTS: The image fusion was successfully applied in all the 17 hepatic colorectal metastases, and on average, 12 min (8-21 min) was spent in the image fusion. One tumor (1/17, 14.3%) received extra one puncture after navigation assisted CEUS. No severe complications and death occurred in all the 12 patients. Complete ablation of the 17 lesions were observed through CT or MRI scan one month after RFA, showing that all the 17 lesions had been completely ablated. CONCLUSION: The real time virtual sonography navigation system had high detection rate for invisible focal liver lesions in B-mode ultrasound. Navigation assisted CEUS could decide whether the area of the ablative zone had covered the whole tumor. Ultrasound CT or MRI navigation and planning system is safe, feasible and accurate in assisting ablation of hepatic colorectal metastases lesions with satisfactory clinical efficacy.

[Laparoscopic liver tumor resection of clinical experience in 126 patients].

OBJECTIVE: To explore the clinical application technology of completely laparoscopy hepodectomy (LH). METHODS: From June 2006 to December 2011, the 126 cases of LH were performed, the data including operating time, blood loss and postoperative complications, etc, were analyzed retrospectively. The patients included 87 males and 39 female and they were 28-83 years old with an average age of 44.5 years old. The parenchyma was transected using laparoscopic ultrasonic scalpel and ligasure, accomplished with endoscopic linear stapler. Of all the patients, the diseases performed LH including primary liver carcinoma (45 cases), liver hemoangioma (58 cases), colon carcinoma with livermetastasis (23 cases), liver focar (5 cases), liver granuloma (1 case), liver adenoma (4 cases). The operations included left hemihepatectomy (n = 17), left lateral lobectomy (n = 34), right hemihepatectomy (n = 15), segmentectomy (n = 22), local resection (n = 59). RESULTS: Of all the patients, mean blood loss was 180 ml (10-1250 ml), mean surgical time was 142 minutes (43-220 minutes), mean postoperative hospital day was 2.2 days (3-12 days). Postoperative complications including eight cases of bile leakage, recovered after 1-3 weeks by appropriately draining. The patients with malignant tumor were followed up for 18 months (12-46 months), recurrence happened in 12 cases and four cases was died of recurrence and metastasis. CONCLUSIONS: LH is a safe, feasible and effective procedure for the treatment of benign liver disease and malignant liver neoplasm as long as the patient is properly selected, it should be recommended for radical resection of hepatocellular carcinoma.

[Analysis and management of the biliary complications after liver transplantations].

OBJECTIVE: To discuss the relevant factors of biliary complications after liver transplantation and to investigate the value of comprehensive management for the complications. METHODS: The data of 366 patients undergoing liver transplantation from October 2000 to March 2012 was analyzed retrospectively, and the risk factors were analyzed by univariate analysis and Stepwise Logistic regression. The cases with biliary leak were administered thorough drainage. The cases with anastomotic biliary stricture were administered sacculus dilatation through percutaneous transhepatic cholangiography (PTC) and endoscopicretrograde cholangiopancreatography (ERCP). If necessary, some cases were placed biliary tract brackets. The patients with nonanastomotic biliary stricture were treated with PTC plus choledochoscope. RESULTS: All the 366 patients were followed up for 58.5 (10 to 129) months. Biliary complications after liver transplantation were diagnosed in 42 cases among these patients. The incidence for biliary complications was 11.5%. The univariate analysis and multivariate Logistic regression analysis showed that the second warm ischemia period and the blood loss and the damage of blood supply and the diameter of biliary anastmosis were significantly associated with biliary complications after liver transplantations (Wald = 9.474 to 17.208, P < 0.05). Twelve cases with biliary leak were cured through abdominal and nasobiliary drainage. Twenty-two cases with anastomotic biliary stricture were administered sacculus dilatation through ERCP or PTC and were cured, including 6 cases were placed biliary tract brackets. Among 8 cases with nonanastomotic biliary stricture, 6 cases were cured through PTC associating with choledochoscope. One case was treated second liver transplantation and another case got worse. CONCLUSIONS: Ischemic injury and the diameter of anastmosis are risk factors for biliary complications after liver transplantations. The interventional management of biliary stricture and bile leakage after liver transplantation is safe and effective.

HBV recurrence lowered by lamivudine/HBIG combination therapy in liver transplant patients: ten-year experience.

BACKGROUND: Lamivudine and hepatitis B immunoglobulin (HBIG) are widely used to treat patients with hepatitis B recurrence after liver transplantation. However, the outcomes are inconclusive. The present study was undertaken to evaluate the effect of combined therapy on patients with hepatitis B recurrence after liver transplantation. METHODS: Twenty-two patients with hepatitis B recurrence after liver transplantation from August 2000 to October 2011 were enrolled in this study. Of these patients, 16 received lamivudine plus HBIG (combination therapy group) and 6 were treated with lamivudine alone (lamivudine-treated group). The clinical features were matched in the two groups. HBV recurrence parameters, HBsAg clearance rate, patient survival rate, and survival time were compared. RESULTS: The average time of follow-up was 47.2 months (range 13-99). Significant difference was noted in the HBsAg clearance rate in the lamivudine-treated and combination therapy groups (50% vs 93.8%, P<0.05). There was no significant difference in the time of HBV recurrence, patient survival rate and survival time between lamivudine-treated and combination therapy groups (P>0.05). CONCLUSION: Compared with lamivudine monotherapy, combination therapy significantly increased the HBsAg clearance rate in patients with HBV recurrence after liver transplantation.

[Clinicopathologic features, diagnosis and treatment with solid-pseudopapillary tumor of the pancreas: a report of 33 cases].

OBJECTIVE: To study the clinicopathologic and immunohistochemical features, biological behavior, diagnosis and treatment of solid pseudopapillary tumor of the pancreas (SPTP). METHODS: A retrospective clinical and clinicopathologic analysis was made on 33 cases of SPTP admitted from May 2001 to 2010 July. There were 7 male and 26 female patients, aging from 13 to 66 years with a mean of 34.3 years. RESULTS: The tumor was located in pancreatic head of 10 patients, in pancreatic neck of 5 patients, in pancreatic body and tail of 18 patients. Of the 33 patients treated with surgery, 8 underwent simple resection of pancreatic tumor, 6 underwent pancreaticoduodenectomy, 3 underwent tumor resection plus pancreaticojejunostomy, 1 underwent tumor resection plus pancreaticogastrostomy, 11 underwent distal pancreatectomy, 4 underwent distal pancreatectomy plus spleen resection (1 underwent mesohepatectomy for hepatic metastasis). Sixteen of the 33 operations were completed by laparoscopy. Histologically, tumors were composed of papillary and microcystic solid structures, with uniformed population of cells. The pancreas and blood vessels invasion were identified in 3 cases, one of them was combined with liver metastasis, and they are male. Immunohistologically, the tumors were positive for α1-antitrypsin, α1-antichymotrypsin, ß-catenin, CD10, CD56 and vimentin (all cases), neuron-specific enolase (3 cases), synaptophysin (6 cases), chromogranin A (4 cases), progesterone receptor (28 cases), estrogen receptor (3 cases), S-100 (6 cases). Totally 33 cases were followed up with a median period of 49 months without tumor recurrence. CONCLUSIONS: SPTP is of low graded malignancy. It primarily affects young women. It may be located in any part of pancreas. Immunohistochemistry is very important for the diagnosis and differential diagnosis of SPTP. Surgical resection is recommended as the treatment of choice. Laparoscopic distal pancreatectomy or tumor resection is feasible and safe for some selected patients, and the prognosis is good.