Solid-pseudopapillary tumor of the pancreas: a neoplasm with distinct and highly characteristic cytological features

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.

Solid pseudopapillary tumor of the pancreas mistaken for gastrointestinal stromal tumor: A case report

Solid pseudopapillary epithelial neoplasms of the pancreas are rare entities, first described in 1959 by Frantz. These tumors represent less than 2% of pancreatic cancers and mainly affect young women. They can reach a significant size and its radiological features can lead to diagnostic pitfalls, such as gastrointestinal stromal tumors, which are rare soft-tissue sarcomas that can appear anywhere along the gastrointestinal tract. Clinicians and radiologists need to be aware of the existing diagnostic pitfalls between these two entities, because of their possible similarities. We report here the case of a 33-year-old woman with a solid pseudopapillary epithelial neoplasms of the pancreas initially misdiagnosed as an exophytic gastric stromal tumor.

Solid pseudopapillary neoplasm of the pancreas: a retrospective study of 195 cases

Objective

Solid pseudopapillary neoplasm of the pancreas (SPN) is a rare exocrine tumor of the pancreas. The aim of our study is to summarize the clinical features of SPN and to analyze the risk factors for malignant SPN.

Methods

From May 2013 to September 2022, patients who were pathologically confirmed to have SPN were retrospectively reviewed. Demographic data, clinical and pathological features, follow-up data were collected and analyzed. To investigate the factors influencing the benign or malignant nature of SPN, we employed logistic regression. Additionally, we utilized Kaplan-Meier curves to depict and analyze the overall prognosis.

Results

A total of 195 patients were included, 163 of whom were female and the average age of all patients was 31.7 years old. Among 195 patients, 101 patients (51.8%) had no obvious clinical symptoms and their pancreatic lesions were detected during routine examination. The primary symptom was abdominal pain and distension in 64 cases (32.8%). The maximum diameter of SPN tumors ranged from 1-17 cm (mean 6.19 cm). Forty-eight postoperative complications developed in 43 (22.1%) patients. After a median follow-up duration of 44.5 months, the overall 5-year survival rate was 98.8% and the recurrence rate was 1.5%. Furthermore, we observed a statistically significant difference in the completeness of the tumor capsule between benign and malignant SPN.

Conclusion

SPN is associated with a favorable long-term survival after surgery in our large sample size cohort. For malignant SPN, tumor capsule incompleteness is an independent risk factor.

Background features in the cytology of pancreatic neoplasms

Cytology is a useful method for diagnosing pancreatic neoplasms. Although endoscopic ultrasound‐guided fine‐needle aspiration has recently become the mainstream method for the diagnosis of pancreatic neoplasms, pancreatic juice and pancreatic duct brushing cytology continue to be useful diagnostic methods for the investigation of pancreatic neoplasms. Diagnoses using pancreatic cytology are primarily based on the features related to tumor cells; however, evaluation of the background features provides important information that could further aid the diagnosis. Pancreatic neoplasms show various histological types, each of which is associated with its own characteristic background features. The necrotic background, desmoplastic stroma, and presence of cancer‐associated fibroblasts are background features of pancreatic ductal adenocarcinoma, a mucinous background is associated with intraductal papillary mucinous neoplasms and mucinous cystic neoplasms, and hyaline globules are observed in solid pseudopapillary neoplasms. However, some background features are associated with more than one histological type of pancreatic neoplasm, highlighting the importance to base a diagnosis on the results of a comprehensive analysis of not only the background features but also the tumor cells. Here, we provide a review of the key background cytological features of pancreatic neoplasms, which can serve as a guide to improve diagnosis and research.

The Sex Features of Patients With Solid Pseudopapillary Neoplasms of the Pancreas: A Retrospective Study

Background

Solid pseudopapillary neoplasms of the pancreas (SPNs) in male patients are more frequently reported. The aim of the study was to evaluate the sex features of SPN and the risk factors that predict tumor recurrence.

Methods

From 2013 to 2019, patients who were pathologically confirmed to have SPNs were retrospectively reviewed. The baseline study parameters were compared between males and females. A logistic regression model was established to identify the independent risk factors for tumor recurrence.

Results

In total, 221 patients were included in this study. Of them, 53 patients (24.0%) were males. Male patients were older than female patients (39.1 vs 31.6 years, P=0.001), and the tumor size in male patients was smaller than that in female patients (50.38 vs 39.65 mm, P=0.038). The preoperative imaging diagnostic accuracy was significantly higher in females than in males (70.5% vs 54%, P=0.02). SPNs in male patients tended to be misdiagnosed with other malignant tumors (37.7% vs 10.7%, P<0.0001), with a more solid component observed in images (66.8% vs 24.7%, P<0.0001). For immunohistochemical staining, the expression of beta catenin was significantly lower in male patients (P=0.002), and the expression of vimentin was the opposite (P=0.01). The overall survival rate and disease-free survival were not different. Based on multivariate analysis, older age [hazard ratio (HR)= 1.094, 95% confidence interval (CI): 1.005-1.190] and KI 67 index grade III (HR=12.029, 95% CI: 2.399-60.311) were independent risk factors for tumor recurrence.

Conclusion

The clinical and imaging features of SPN in males were not in full accord with those in females; however, the differences did not influence prognosis.

Cytological Diagnosis of Pancreatic Solid-Pseudopapillary Neoplasm: A Single-Institution Community Practice Experience

Introduction. Pancreatic solid-pseudopapillary neoplasm (SPN) is a rare tumor that typically occurs in young females. Although a cytological diagnosis may be easily made in this age group when there are typical features, atypical clinical presentations and unusual cytological features may make this a challenging diagnosis. We present our single-institution experience in a cohort of these tumors, outlining both typical and atypical features. Awareness of unusual clinical and cytological features can help to avoid pitfalls during diagnosis. Methods. We performed a review of all cases of pancreatic SPNs diagnosed over a 15-year period (January 2007 to December 2021). Detailed cytological, clinical, and follow-up histological features were presented and analyzed. Results. Twenty-two cases of SPN were diagnosed at our institution during this 15-year period. Patients ranged from 12 to 73 years of age (mean 33 y, median 26 y) and included 19 females and 3 males. Seventeen patients had cytological material, and fourteen were diagnosed by EUS-FNA. Typical cytological features included papillary clusters with central capillaries, myxoid stroma, monomorphism, cercariform cells, and hyaline globules. Atypical or unusual cytological features that were seen in a few cases were multinucleated giant cells, clear cells, and/or foamy macrophages. A few cases showed features that were similar to pancreatic neuroendocrine tumors (PanNETs). Tumor cells were always positive for β-catenin, CD10, CD56, cyclin-D1, progesterone receptor (PR), and vimentin by immunohistochemistry. They were always negative for chromogranin. Pancytokeratin and synaptophysin stains were positive in 9% and 46% of cases evaluated, respectively. All cases had histological confirmation on resection. The median follow-up duration was 69 months (a range of 2–177 months), with only three cases lost to follow-up. No recurrence or metastasis was identified. Conclusions. We present our experience with cytological diagnoses of SPN in a well-characterized cohort of 22 patients with histological correlation and follow-up data. These tumors occur over a wide range and show varied cytological features. SPNs can be confidently diagnosed on limited cytological material, with limited panel immunohistochemistry aiding diagnosis in atypical cases. Recognizing the associated degenerative changes is crucial in avoiding a misdiagnosis.

Solid Pseudopapillary Neoplasm of the Uncinate Process of the Pancreas: A Case Report and Review of the Literature

Solid pseudopapillary neoplasm (SPN) is a rare pancreatic neoplasm that accounts for 1-3% of all pancreatic tumors. SPNs are most commonly found in females in their third and fourth decades of life. Even though the majority of the tumors are benign, malignant tumors have also been reported. Given its rare occurrence, it remains a clinical dilemma in gastroenterology, oncology, and pathology. It is critical to diagnose it early and differentiate it from other similar pancreatic tumors or cysts to ensure favorable patient outcomes. Advanced imaging techniques, characteristic histologic findings, and immunohistochemical analysis can help in diagnosing solid pseudopapillary tumors. Early diagnosis and surgical resection can result in a cure in most cases, and tumor recurrence is extremely rare. In this report, we present a case of a 40-year-old female patient who presented to the emergency room and was diagnosed with SPN of the pancreas.

A Rare Case of Solid Pseudopapillary Neoplasm of the Pancreas

Solid pseudopapillary neoplasm of pancreas (SPN) is a rare entity. It is almost exclusively seen in females within the second and third decades of life with only small minority affecting children. Due to the paucity of the number of cases seen, the natural history of the disease is not fully understood. SPN tumors of the pancreas are usually found incidentally and usually have an excellent prognosis. We herein present a case of a 33-year-old lady diagnosed with SPN, who presented with abdominal fullness, two weeks post cesarean section.

Solid pseudopapillary neoplasms of the pancreas: Case series with a review of the literature

BACKGROUND/AIMS

The solid pseudopapillary neoplasms are quite rare tumors of the pancreas, comprising roughly 1-2% of all pancreatic neoplasms. It has a low malignant potential and usually affects young females. Despite increasing number of articles in the last decade, there is still debate on the pathogenesis, malignant potential and optimal surgical strategy for the solid pseudopapillary neoplasms.

MATERIALS AND METHODS

Medical recordings of 326 patients who were operated due to pancreatic mass were retrospectively analyzed. Patient demographics, presenting symptoms, surgical and pathologic characteristics of the tumor, postsurgical course, long-term survival, and other relevant data were extracted from patients' charts.

RESULTS

Majority of the patients were female in consistency with the classic data in the literature. All the patients underwent curative intent resections. Tumors were commonly localized in the tail of the pancreas making distal pancreatectomy the most commonly performed surgical procedure. Mean tumor diameter was 5.8 centimeters with tumor sizes ranging from 1 to 19 cm.

CONCLUSION

The solid pseudopapillary neoplasms of the pancreas is a rare tumor with low malignant potential, which is more common in females of reproductive age, with abdominal pain being their most common presentation. The short-term outcomes in patients following surgical R0 resection are excellent. However, proximal placement of the tumor and female gender may have slightly worse prognosis. We hope that our findings from a series of patients represent a contribution to the existing literature on SPN, and authors declare their willingness to provide further details for future meta-analyses.

Sex differences in solid pseudopapillary neoplasm of the pancreas: A population-based study

Objective

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor. This study aims to examine the clinicopathological features and surgical treatments of SPN and compare the clinical behavior and prognosis between men and women with SPN.

Methods

We collected the population data of patients with SPN diagnosed between 2004 and 2017 from the SEER database. The Kaplan‐Meier method was used to analyze overall survival (OS) and disease‐specific survival (DSS), and log‐rank tests were used to evaluate the differences between subgroups. Univariate and multivariate Cox regression analyses were performed to screen out prognostic risk factors of SPN.

Results

A total of 378 patients with SPN were included, with 246 (65.1%) female patients. 1‐, 3‐, and 5‐year overall survival rates were 98.9%, 95.7%, and 93.7%, respectively. Survival analysis revealed that regardless of stage, patients with SPN who underwent surgical interventions still had a significantly better prognosis than those without surgical interventions (P < .001). The patients with lymphatic dissection had a significantly better prognosis than those without lymphatic dissection (P < .001). Moreover, compared with female patients, male patients had significantly poorer OS and DSS (P < .001). Female SPN showed a bimodal age‐frequency distribution with early‐onset incidence at 28 years and late‐onset peak incidence at 62 years, while male SPN presented a unimodal distribution with peak incidence at approximately age 64 years. In female patients, the tumor size in premenopausal females (<65 years old) was significantly larger than that in postmenopausal females (≥65 years old) (P < .001). Clinicopathological characteristic profiles were different not only between male SPN and premenopausal female SPN but also between premenopausal and postmenopausal female SPN.

Conclusion

SPN presents indolent behavior and predominantly occurs in young women. Regardless of stage, surgical intervention is recommended. Moreover, our study is the first large enough study to demonstrate sex‐related discrepancies in SPN. Thus, different treatment strategies should be designed for patients of different sexes at different ages and hormone therapy is a promising approach for SPN.

Fine needle aspiration cytology with the aid of immunocytochemistry on cell-block confirms the diagnosis of solid pseudopapillary neoplasm of the pancreas

INTRODUCTION

To determine the diagnostic efficacy of fine needle aspiration cytology (FNAC) in cases of pancreatic solid pseudopapillary neoplasm (PSPN) with emphasis on the cytomorphological features and to evaluate the contribution of immunocytochemistry on FNAC cell-block (CB) in cases of PSPN.

METHODS

It is a retrospective study in which ultrasound-guided FNAC of pancreatic lesions diagnosed as PSPN between years 2009 and July 2019 were reviewed along with cytohistological correlation. Immunocytochemistry on CB was performed, wherever required.

RESULTS

A total of 16 patients with a cytological diagnosis of PSPN of the pancreas were identified. The most common cytological findings were characteristic branching pseudopapillary fragments with central thin, delicate capillaries associated with the amorphous myxoid substance, surrounded by tumour cells with mild pleomorphism. Immunocytochemistry was performed on CB of six cases. The tumour cells revealed nucleocytoplasmic positivity for β-catenin, cytoplasmic positivity for vimentin, membranocytoplasmic positivity for CD10 and nuclear positivity for progesterone receptor in all the cases, while they were negative for chromogranin, CD56, pan-cytokeratin and epithelial membrane antigen. The resected histopathological specimen was available in 10cases, and all were confirmed as PSPN.

CONCLUSION

Although PSPN has a characteristic cytomorphology, cell-block immunocytochemistry on FNA material confirms the diagnosis in problematic cases and excludes other pancreatic tumours, thus helping in appropriate management.

A systematic review and meta-analysis of predictors of recurrence in patients with Solid Pseudopapillary Tumors of the Pancreas

BACKGROUND

The recurrence rates and predictors of recurrence in patients with Solid Pseudopapillary tumors (SPT) are unclear, which makes it challenging to determine the duration of follow-up. The aim of the current study was to perform a systematic review and meta-analysis to determine the recurrence rates and pathologic factors associated with recurrence in patients with SPT.

METHODS

A PubMed, Scopus, and Web of Science search was conducted to identify studies of SPT published during the last 15 years: (09/2002-09/2017). Studies reporting on patients with SPT and follow-up of >5 years were included. The search strategy was conducted per 2009 PRISMA guidelines.

RESULTS

A total of 103 studies reporting on 2599 non-metastatic SPT patients were identified. Sixty-nine patients (2.6%) developed recurrence during follow-up. Pooled estimates from studies with a sample size >20 (N = 33) noted an overall recurrence rate of 2% (95% CI 1-2%). Male gender (OR 1.960), positive lymph nodes (OR 11.9), R1 margins (OR 11.1), and LVI (OR 5.5), were associated with a significantly (all p < 0.05) increased risk of recurrence.

CONCLUSION

Current meta-analysis suggests that only 2% of patients with SPT experience recurrence after resection. These data will guide the treating physicians and patients regarding recurrence rates and help identify patients at increased risk of recurrence during follow-up.

Prognostic value of progesterone receptor in solid pseudopapillary neoplasm of the pancreas: evaluation of a pooled case series

Background

The role of progesterone receptor (PR) has been reported in a series of pancreatic cysts. However, the relationship between PR and prognosis of solid pseudopapillary neoplasm of the pancreas (SPNP) has not been elucidated so far. The aim of our study was to evaluate the prognostic value of PR in SPNP.

Methods

A total of 76 patients with SPNP treated in our institution from January 2012 to December 2017 were included. Demographic parameters, laboratory data, pathologic information and clinical outcomes were analyzed by the use of survival analysis. In addition, a pooled case series was performed to evaluate the results.

Results

The institutional data included 76 patients (17 male and 59 female) ranging from 8 to 90 years (median, 30 years) in age. Kaplan-Meier survival analysis confirmed negative PR result was significantly associated with poorer disease-free survival (DFS) and disease-specific survival (DSS) (both P < 0.001). In the pooled analysis, a total of 62 studies comprising 214 patients with SPNP were included. After multivariable cox analysis, negative PR result remained an independent prognostic factor for SPNP (DFS HR: 14.50, 95% CI: 1.98–106.05, P = 0.008; DSS HR: 9.15, 95% CI: 1.89–44.17, P = 0.006).

Conclusion

Our results indicated the role of PR in predicting adverse outcome of patients with SPNP and negative PR result may serve as a potential prognostic factor.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0914-8) contains supplementary material, which is available to authorized users.

Solid Pseudopapillary Tumor of the Pancreas: A Single-center Experience and Review of the Literature

BACKGROUND

Solid pseudopapillary tumors (SPTs) of the pancreas are a rare occurrence, not exceeding 1-2% of all exocrine pancreatic tumors. SPT was first described in 1959 as "papillary tumor of the pancreas, benign or malignant" and affects mainly young women, in their second or third decade of age. These tumors are of low malignant potential, unclear pathogenesis, grow gradually and become considerably large before causing symptoms. A typical clinical presentation is often described by affected patients and, in some cases, an SPT is an incidental finding during the time the patient undergoes medical imaging studies for other health issues. SPT is frequently located at the head or tail of the pancreas. Metastases are rare but, when present, affect predominantly the liver.

PATIENTS AND METHODS

We report a series of five SPT cases in female patients 13-47 years old, presenting with almost identical symptoms of upper abdominal discomfort and non-tender palpable mass. Two out of five patients also reported vomiting, nausea and poor appetite as co-existing non-diagnostic symptoms. Only one patient presented without any symptoms. Tumor location and dimensions varied. One patient underwent a pancreatoduodenectomy (Whipple's procedure), while the remaining patients underwent distal pancreatectomy with concomitant splenectomy.

RESULTS

Perioperative morbidity and mortality was zero. All five patients are disease-free at a follow-up from 3 months to 13 years. Histopathology reports supported the diagnosis of SPT and no metastatic disease was present in any of the patients.

CONCLUSION

The overall prognosis of SPT of the pancreas is excellent due to its favorable biological features, even in the presence of distal metastasis. Although surgical resection is often curative, a close follow-up is advised in order to diagnose a possible local recurrence or distal metastasis and choose the proper therapeutic option for the patients.

Situs inversus totalis with solid pseudopapillary pancreatic tumor: A case report and review of literature

RATIONALE

Situs inversus totalis (SIT) is a rare anatomical variation of the internal organs, and solid pseudopapillary tumor of the pancreas (SPTP) is a rare tissue type of pancreatic tumors, classified as benign or low-grade malignancy. However, to our knowledge, a patient with SIT and SPTP is extremely rare and has never been reported.

PATIENT CONCERNS

We retrospectively analyzed a case of SIT with SPTP in a 45-year-old woman. The main complaints were abdominal pain and sensation of heaviness for 2 weeks. There was tenderness and a mass that could be palpated in the right upper abdomen.

DIAGNOSES

Heart ultrasonography (USG), chest x-ray, computed tomography (CT), and contrast-enhanced computerized tomography (CECT) revealed a mirror-image dextrocardia and inversion of all abdominal viscera and a space-occupying lesion in the pancreas tail. Abdominal computed tomography angiography (CTA) showed no obvious abnormality of artery. The diagnosis of SPTP was finally made by postoperative pathological examination.

INTERVENTIONS

The patient underwent resection of the pancreatic body and tail and splenectomy via laparotomy to completely remove the tumor.

OUTCOMES

The patient was discharged with specific discomfort on postoperative day 7. At the 1.5-year follow-up, she recovered without issue.

LESSONS

Surgical resection remains the only effective treatment of SPTP. SIT with SPTP can be accurately diagnosed by heart USG, chest x-ray, CT, and CECT of the upper abdomen. Abdominal aorta CTA before surgery can decrease the injury risk of blood vessels.

Solid Pseudopapillary Neoplasms of the Pancreas: A Surgical and Genetic Enigma

Solid pseudopapillary neoplasms of the pancreas are rare tumors accounting for 1-2% of pancreatic exocrine neoplasms. This entity was first described by Dr. Frantz in 1959 and was defined by the World Health Organization in 1996 as "solid pseudopapillary tumor." It is most often a benign neoplasm, but 10-15% of the cases are malignant. Over the past decades, the incidence of this tumor is increasing. However, many surgeons are still unfamiliar with this neoplasm and its unique characteristics, which can lead to pitfalls in the diagnosis and treatment. The correct diagnosis of SPNP is of utmost importance since it has a low malignant potential and with the appropriate treatment, patients have a long life expectancy. There are many genetic alterations, involving various signaling pathways that have been associated with SPNP and are very important in diagnosing the tumor. The cornerstone of SPNP treatment includes surgical excision of the tumor, preserving as much pancreatic tissue as possible. We review the information in the literature regarding more organ-preserving techniques and possible clinical features that might indicate a malignant potential, thus demanding a more radical intraoperative excision.

Highly Accurate Identification of Cystic Precursor Lesions of Pancreatic Cancer Through Targeted Mass Spectrometry: A Phase IIc Diagnostic Study

Purpose Pancreatic cystic lesions are common incidental findings on imaging, but up to half may be forerunners of pancreatic cancer. Therefore, accurate differential diagnosis is crucial for correct patient management. Unfortunately, currently available diagnostic methods cannot robustly identify premalignant and malignant pancreatic cystic lesions. Methods Cyst fluid samples obtained by routine endoscopic ultrasound-guided aspiration were used for the analyses. In a cohort of 24 patients, eight biomarker candidates for malignant potential and high-grade dysplasia/cancer were identified by an explorative proteomic approach. Subsequently, a quantitative analysis, using 30 heavy-labeled peptides from the biomarkers and parallel reaction monitoring mass spectrometry, was devised, tested in a training cohort of 80, and prospectively evaluated in a validation cohort of 68 patients. End points were surgical pathology diagnosis/clinical follow-up. Diagnostic assessments were blinded to mass spectrometry results. Results The optimal set of markers for detecting malignant potential was a panel of peptides from mucin-5AC and mucin-2, which could discriminate premalignant/malignant lesions from benign with an accuracy of 97% (95% CI, 89% to 99%) in the validation cohort. This result compared favorably with the accuracy of standard analyses: cyst fluid carcinoembryonic antigen (61%; 95% CI, 46% to 74%; P < .001) and cytology (84%; 95% CI, 71% to 92%; P = .02). A combination of proteins mucin-5AC and prostate stem-cell antigen could identify high-grade dysplasia/cancer with an accuracy of 96% (95% CI, 90% to 99%), and detected 95% of malignant/severely dysplastic lesions, compared with 35% and 50% for carcinoembryonic antigen and cytology ( P < .001 and P = .003, respectively). Conclusion Targeted mass spectrometry analysis of just three cyst fluid biomarkers provides highly accurate identification and assessment of cystic precursors to pancreatic adenocarcinoma. Additional studies should determine whether the method can facilitate timely cancer diagnosis, successful intervention, and prevention.

Cytologic criteria to reduce error in EUS-FNA of solid pseudopapillary neoplasms of the pancreas

INTRODUCTION

Standardization of error classification in pathology remains an important issue. This study assesses the extent of error in cytopathologic diagnosis of solid pseudopapillary neoplasms (SPN) of the pancreas. Because of morphologic overlap of SPN and pancreatic neuroendocrine neoplasms (NET), we compared cytologic characteristics to determine which best distinguishes these entities.

MATERIALS AND METHODS

We collected cases diagnosed as SPN either by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) by cytology or surgical pathology from January 2000 to March 2013. An equal number of NET cases were randomly selected. Cytology and surgical pathology cases were evaluated for diagnostic errors and patient impact. Cytologic features in SPN and NET were scored based on presence of previously described characteristics.

RESULTS

A total of 17 patients with EUS-FNA were diagnosed with SPN by cytology or surgical pathology. Of those, 14 had surgical follow-up and 13 had adequate cell blocks and immunohistochemistry. There were 5 discrepancies between cytology and surgical pathology (5 of 14, 36%). There were no false positives or false negatives, but 5 misclassifications: 4 diagnosed as NET on cytology, and 1 as NET versus SPN. All misclassification errors were associated with no harm. When compared with NET, fine chromatin, nuclear grooves, pseud papillae, pink stroma, and hyaline globules are statistically significantly associated with SPN.

CONCLUSIONS

EUS-FNA of pancreatic SPN has excellent positive and negative predictive value, with no false positives or false negatives in this 12-year study. Only misclassification errors as pancreatic NET were made with minimal impact. We suggest that the presence of 3 of 5 major cytologic criteria offer accuracy in diagnosing SPN to prevent misclassification.

A, Lima S, Cardoso E, Brito E, Macedo-Lima M, Lyra Jr. D, Lyra P, Lima MM. Solid pseudopapillary tumor of the pancreas: Clinical features, diagnosis and treatment

Summary Introduction: Solid pseudopapillary tumor of the pancreas (SPTP) is a rare neoplasm of low malignant potential with uncertain behavior, diagnosed mainly in young women. Method: Our report comprises a series of cases of SPTP reviewed retrospectively, highlighting clinical, tomographic and immunohistochemical features, treatment performed and outcomes. Results: Thirteen patients were found to have pancreatic [solid] masses on computed tomography scan measuring a mean diameter of 8.8 cm. All patients underwent complete surgical excision. Immunohistochemistry confirmed diagnosis in all cases. Conclusion: SPTP occurs more frequently in young women. Diagnostic suspicion lies on the finding of a bulky, solid and cystic pancreatic mass. Imaging findings might provide diagnostic information before resection. Conservative approaches can be used in selected cases and survival rates are usually excellent following complete resection.

Solid pseudopapillary neoplasm of the pancreas: Management and long-term outcome

BACKGROUND

Solid pseudopapillary neoplasm (SPN) of pancreas is a rare pancreatic neoplasm with a low metastatic potential. Our aim was to study the clinical-pathological characteristics, and long-term outcome of this tumor.

MATERIALS

Rretrospective single center study of patients operated for SPN of pancreas. Clinical and pathological data were collected.

RESULTS

From 1995 to 2016, 1320 patients underwent pancreatic resection. SPN was confirmed in 32 cases (2.46%), including 29 (90.6%) female and three (9.4%) male, with a mean age of 28.4 ± 12.2 years. SPN was the most common pathology among female patients under age of 40 (72.4%). Abdominal pain was the most frequent presenting symptom (48%), whereas none of the patients presented with jaundice. Mean tumor diameter was 5.9 cm (range, 0.9-14 cm). All patients underwent margin-negative surgical resection. Two patients demonstrated gross malignant features, including liver metastases at presentation (n = 1), and adjacent organ and vascular invasion (n = 1). Microscopic malignant features were present in thirteen patients (40.6%). Recurrence occurred in the retroperitoneal lymph nodes (n = 1, 7 years post resection) and in the liver (n = 2, 1 and 5 years post resection). Mean follow-up was 49.2 months (range, 1-228 months). Five and 10-year disease-free survival was 96.5% and 89.6% respectively.

CONCLUSIONS

SPNs are low-grade tumors with a good prognosis. Margin-negative surgical resection is curative in most patients. However, almost 15% of patients demonstrate malignant features including invasion of adjacent organs or metastatic disease. Patients with malignant disease are still expected to have long survival, and aggressive surgical approach is advocated.

A solid pseudopapillary neoplasm of the pancreas in a man presenting with acute pancreatitis: A case report

INTRODUCTION

A solid pseudopapillary neoplasm (SPN) of the pancreas is rare neoplasm that occurs predominantly in young women. The clinical presentation of SPNs is nonspecific, but acute pancreatitis is rare in the reported literature.

PRESENTATION OF CASE

A 36-year-old man was referred to our hospital because of upper abdominal pain and elevation of serum amylase. A computed tomography (CT) scan showed swelling of the pancreas body and a poorly enhanced and indistinct mass in the pancreas body. He was diagnosed with acute pancreatitis. The symptom was improved with conservative treatment, but acute pancreatitis recurred twice during a period of 2 months. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) showed stenosis of the MPD adjacent to the mass. Distal pancreatectomy was performed because the mass in the pancreas body seemed to cause repeated acute pancreatitis and malignant pancreatic cancer could not be excluded. Immunohistochemically, a diagnosis of SPN of the pancreas was made from the resected specimen.

DISCUSSION

To the best our knowledge, only 6 cases have been reported in the literature concerning the SPN presenting with acute pancreatitis.

CONCLUSION

We report a man with a small SPN of the pancreas presenting with acute pancreatitis and mimicking pancreatic cancer. We should be aware that this rare pancreatic tumor can become a cause of acute pancreatitis.

Solid pseudopapillary tumor of pancreas: A lesser known entity-diagnosis and pitfalls: A case report

Solid pseudopapillary tumor (SPT) is a rare pancreatic neoplasm with a reported incidence of 0.1% to 2.7% of all pancreatic tumors. Because radiological presentation of pancreatic tumors is quite overlapping, distinctive features in fine needle aspiration cytology (FNAC) helps in its diagnosis preoperatively. Being a low-grade malignancy presenting predominantly in young females, correct preoperative diagnosis minimizes the need of extensive surgery. SPT carries good prognosis without any adjuvant chemotherapy/radiotherapy in most cases, even in the presence of metastatic disease. On the other hand, aggressive surgical resection is required for ductal adenocarcinoma which is more common pancreatic tumor (90%). We report here a case of a 49-year-old female diagnosed as SPT. The importance of the need for the radiologist, pathologist, and surgeon to be familiar with SPT is highlighted so that it is more often diagnosed as there are significant therapeutic and prognostic implications.

Pancreatic Cytopathology

Pancreatic cytopathology, particularly through the use of endoscopic ultrasound-guided fine-needle aspiration (FNA), has excellent specificity and sensitivity for the diagnosis of pancreatic lesions. Such diagnoses can help guide preoperative management of patients, provide prognostic information, and confirm diagnoses in patients who are not surgical candidates. Furthermore, FNA can be used to obtain cyst fluid for ancillary tests that can improve the diagnosis of cystic lesions. In this article, we describe the cytomorphological features and differential diagnoses of the most commonly encountered pancreatic lesions on FNA.

[Solid pseudopapillary tumour of the pancreas: about a case and review of the literature]

Solid pseudopapillary tumours of the pancreas are rare tumours of uncertain etiology which mostly affects young women. Their prognosis is good especially after complete resection. We report a new case of a young woman; abdominal pain revealed solid pseudopapillary tumour. The diagnosis is based on histological examination associated with immunohistochemistry of the piece of resection removed with caudal splenopancreatectomy.

Laparoscopic distal pancreatectomy for solid-pseudopapillary tumor of the pancreas

PURPOSE

Solid-pseudopapillary tumor (SPT) of pancreas is a rare entity with a low malignant potential. We aimed to identify the safety and the feasibility of laparoscopic distal pancreatectomy for SPT.

METHODS

From May 2008 to August 2011, we performed 4 cases of laparoscopic, spleen-preserving, distal pancreatectomies for patients with SPT. We retrospectively collected the demographic characteristics, operative and postoperative details, and follow-up outcomes of the patients.

RESULTS

Three female patients and 1 male patient with SPT underwent laparoscopic, spleen-preserving, distal pancreatectomy. The average operating time was 200 minutes. The average blood loss was 90 mL. The postoperative course of these patients was uneventful. All patients were followed-up and no local recurrence or metastasis was found.

CONCLUSIONS

Laparoscopic distal pancreatectomy for patients with SPT is safe and feasible, with preferable operative outcomes, long-term tumor-free survival, and high spleen-preserving rate.

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

Objectives

To evaluate the clinical characteristics and radiological features of solid pseudopapillary tumor (SPT) and assess surgical therapy strategy.

Methods

A 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.

Results

56 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.

Conclusions

Solid 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.

A pancreatic pseudopapillary tumor enucleated curatively

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Pancreatic pseudopapillary tumor is an rarely problem.

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Tumor may be more aggressive at males relatively to females.

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Complete resection is the main treatment option for these tumors.

Introduction

Pseudopapillary tumors (PPT) of the pancreas are very rare, comprising 0.3–2.7% of all pancreatic tumors, and they occur mostly in young women. Generally, they are benign, but in rare cases they can enlarge, invade adjacent organs, and metastasize distantly. Radiological assessments and biochemical markers are important for diagnosing tumor characteristics. The main treatment is tumor resection.

Presentation of case

An 18-year-old female was referred to our department suffering from abdominal discomfort and upper quadrant abdominal pain. Abdominal computed tomography (CT) revealed a 6- × 5-cm mass between the pancreatic head and right adrenal gland (Fig. 1). The histological assessment was a solid PPT of the pancreas with intact surgical borders.

Discussion

PPT are very rare, comprising approximately 5% of cystic pancreatic tumors and ∼1% of exocrine pancreatic neoplasms and present mainly during the second and third decades of life. PPTs are usually indolent tumors. As such, they tend to produce vague nonspecific symptoms or may be detected incidentally on imaging. Complete surgical resection (R0) is the most effective therapy for PPT.

Conclusion

Although PPT is a very rare, benign tumor, it has the potential to metastasize to adjacent and distant organs. Consequently, they should be detected early, so that they can be treated surgically before malignant conversion.

Epidemiological characteristics, diagnosis and treatment of solid pseudopaillary neoplasm of the pancreas in China in the past 20 years

AIM: To review the epidemiological characteristics, diagnosis and treatment of solid pseudopaillary neoplasm of the pancreas (SPN) in the past 20 years.

METHODS: The reports about SPN were serached, and the information relevant to epidemiological features, diagnosis and treatment of SPN, as well as the clinical data were retrieved and analyzed retrospectively.

RESULTS: A total of 3688 patients with SPN were reported in China from January 1995 to April 2014. The ratio of males to females was approximately 1:6.65; the average age was 30.11 years. About 39.59% of the patients were distributed in east China. The patients with symptoms accounted for approximately 74.73%; 3.23% of the patients were reported with jaundice. Tumor markers were negative in nearly all the patients. About 29.42% of the patients were diagnosed as SPN prior to surgery. The tumors were observed frequently in the head and neck (40.22%), the body and tail (58.98%) of the pancreas. The main treatment for SPN was surgery, including enucleation (41.12%), pancreatoduodenectomy (23.41%) and distal pancreatectomy with splenectomy (34.23%). The positive rates of vimentin, α1-antitrypsin (α1-AT) and α1-antichymotrypsin (α1-ACT) in tumor cells were 92.25%, 90.81% and 87.06%, respectively. Postoperative recurrence developed in 175 cases; 17 cases died of SPN.

CONCLUSION: SPN occurs predominantly in young females and is more prevalent in east China. SPN lacks specific symptoms or signs, has diverse imaging manifestations, and can be easily misdiagnosed. Definite diagnosis in most patients relies on pathology and immunohistochemistry. SPN is a neoplasm of low malignant potential. Surgical procedure is the main effective treatment with good prognosis.

A solid pseudopapillary neoplasm without cysts that occurred in a patient diagnosed by endoscopic ultrasound-guided fine-needle aspiration: a case report

Introduction

Solid pseudopapillary neoplasm of the pancreas is a rare neoplasm that has been reported to account for between 0.17% and 2.7% of all non-endocrine tumors of the pancreas. It is usually seen in young women. Because solid pseudopapillary neoplasms are rarely aggressive and have low-grade malignant potential and an excellent prognosis after complete resection, it is an ideal pancreatic tumor for treatment by minimally invasive surgery. Therefore, making an accurate pre-operative diagnosis is very important.

Case presentation

A 24-year-old Japanese man who had been found to have mild transaminase elevations at a medical check-up visited our hospital for further examination. Abdominal computed tomography showed a 40mm-diameter tumor in the pancreatic tail and mild fatty liver. He was admitted to our hospital for additional examination. The abdominal contrast-enhanced computed tomography scan taken at our institution showed an increasingly enhanced mass of 40mm diameter in the pancreatic tail. Ultrasonography showed a low-level echoic mass of 35mm diameter in the pancreatic tail. T1-weighted magnetic resonance imaging showed low signal intensity in the tail of the pancreas. T2-weighted magnetic resonance imaging showed high signal intensity there. Diffusion magnetic resonance imaging showed high signal intensity. An endoscopic ultrasound yielded the same results as the abdominal ultrasonogram. In addition, [¹⁸F]-fluorodeoxyglucose positron emission tomography/computed tomography showed abnormal accumulation (maximum standardized uptake value, 6.53). This finding raised our suspicion of a pancreatic malignant tumor. However, the patient could not be confidently diagnosed solely on the basis of imaging. Endoscopic ultrasound-guided fine-needle aspiration was performed, which led us to a diagnosis of solid pseudopapillary neoplasm. On that basis, we performed minimally invasive surgery (spleen-preserving laparoscopic distal pancreatectomy).

Conclusion

Atypical solid pseudopapillary neoplasm without cysts should be considered when diagnosing pancreatic tumors. A definitive pre-operative diagnosis of solid pseudopapillary neoplasm made on the basis of endoscopic ultrasound-guided fine-needle aspiration can guide the surgical approach used.

Solid pseudopapillary neoplasms of the pancreas: a report of two cases

Solid pseudopapillary neoplasms of the pancreas are uncommon, accounting for only 1-2% of all pancreatic neoplasms. These tumors are being detected at an increased rate, probably due to the increased awareness and the liberal use of imaging. We report two cases of patients with solid pseudopapillary pancreatic tumors and review the existing literature.

Proteomic mucin profiling for the identification of cystic precursors of pancreatic cancer

BACKGROUND

Pancreatic cystic lesions (PCLs) are increasingly frequent radiological incidentalomas, with a considerable proportion representing precursors of pancreatic cancer. Better diagnostic tools are required for patients to benefit from this development.

METHODS

To evaluate whether cyst fluid mucin expression could predict malignant potential and/or transformation in PCLs, a proteomic method was devised and prospectively evaluated in consecutive patients referred to our tertiary center for endoscopic ultrasound-guided aspiration of cystic lesions from May 2007 through November 2008 (discovery cohort) and from December 2008 through October 2012 (validation cohort). Cytology and cyst fluid carcinoembryonic antigen (CEA; premalignancy > 192 ng/mL, malignancy > 1000 ng/mL) were routinely analyzed, and samples were further processed as follows: one-dimensional gel electrophoresis, excision of high-mass areas, tryptic digestion and nano-liquid chromatography-tandem mass spectrometry, with peptide identification by Mascot software and an in-house mucin database. All diagnostic evaluations were blinded to proteomics results. Histology was required to confirm the presence/absence of malignant transformation. All statistical tests were two-sided.

RESULTS

Proteomic mucin profiling proved statistically significantly more accurate (97.5%; 95% confidence interval [CI] = 90.3% to 99.6%) than cytology (71.4%; 95% CI = 59.8% to 80.9%; P < .001) and cyst fluid CEA (78.0%; 95% CI = 65.0% to 87.3%; P < .001) in identifying the 37 (out of 79; 46.8%) lesions with malignant potential (ie, premalignant or malignant tumors). The accuracy of proteomics was nearly identical (96.6% vs 98.0%) between the discovery (n = 29) and validation (n = 50) cohorts. Furthermore, mucin profiling predicted malignant transformation, present in 16 out of 29 (discovery cohort: 9, validation cohort: 20) lesions with available histology, with 89.7% accuracy (95% CI = 71.5% to 97.3%) (for the validation cohort only: 95.0%; 95% CI = 73.1% to 99.7%). This markedly exceeded corresponding results for cytology (51.7%; 95% CI = 32.9% to 70.1%; P = .003) and CEA (57.1%; 95% CI = 34.4% to 77.4%; P = .02).

CONCLUSIONS

Proteomic cyst fluid mucin profiling robustly discriminates benign, premalignant, and malignant PCLs. Consequently, it may improve pancreatic cancer prevention and reduce the morbidity burden of unwarranted pancreatic surgery.

Solid pseudopapillary tumor of the pancreas in children: 15-year experience at a single institution with assays using an immunohistochemical panel

PURPOSE

The aim of this study was to analyze the clinicopathological characteristics of solid pseudopapillary tumor (SPT) of the pancreas and to utilize an immunohistochemical panel to identify specific markers of the disease.

METHODS

Eleven patients diagnosed with and treated for SPT of the pancreas over the past 15 years were retrospectively analyzed.

RESULTS

The 11 patients consisted of 8 females and 3 males, of mean age at operation of 13.5 years (range, 10 to 18 years). The most frequent presenting symptom was abdominal pain and/or mass. One patient was referred with hemoperitoneum due to traumatic tumor rupture. The lesions were located in the body, head and tail of the pancreas in four, four, and three patients, respectively. Mean tumor diameter was 7.9 cm (range, 2.5 to 15 cm). Surgical procedures included distal pancreatectomy with splenectomy in four patients, pylorus preserving pancreaticoduodenectomy in four, distal pancreatectomy in two, and subtotal pancreatectomy with splenectomy in one. Mean follow-up was 60.5 months (range, 15 to 126 months). All patients remain alive without tumor recurrence. Immunohistochemical staining showed that all tumors were positive for β-catenin, progesterone receptor (PR), vimentin, and CD99. However, all tumors were negative for E-cadherin and cytokeratin 7 expression.

CONCLUSION

Patients with SPT of the pancreas have an excellent prognosis after surgical excision. Immunohistochemically, E-cadherin/β-catenin, PR, vimentin, and CD99 would help establish the diagnosis of SPT of the pancreas, although the results of immunohistochemical staining were found to have an indistinct complex immunoprofile.

Clear cell variant of solid pseudopapillary neoplasm of pancreas diagnosed by fine needle aspiration: A case report and review of the literature

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor of uncertain malignant potential, predominantly affecting young adult females. We report a case of clear cell variant of SPN, which was diagnosed by fine needle aspiration biopsy. The aspirate was highly cellular and exhibited delicate branching papillary structures with central capillaries covered with several layers of plasmacytoid tumor cells. Acinar and rosette-like formations, as well as single neoplastic cells were also observed. An unusual cytologic feature was the presence of large, clear cytoplasmic vacuoles. The diagnosis of SPN was confirmed by characteristic immunocytochemical staining pattern including nuclear staining for β-catenin, cytoplasmic staining for vimentin and lack of reactivity for cytokeratin.

CD 99 immunocytochemistry in solid pseudopapillary tumor of pancreas: A study on fine-needle aspiration cytology smears

BACKGROUND

Solid pseudopapillary tumor of pancreas (SPTP) is a rare pancreatic tumor of uncertain histogenesis usually affecting young women. Though these tumors have characteristic cytomorphology, it is sometimes difficult to differentiate them from neuroendocrine tumors of the pancreas. We reviewed cases of SPTP to delineate the diagnostic cytological features and also observed utility of CD 99 (MIC 2) immunostaining to aid in the diagnosis of this tumor.

AIMS

This study was designed to demonstrate the utility of CD 99 immunostaining along with cytological features for making a pre-operative diagnosis and delineating it from the neuroendocrine tumor of pancreas which is a close mimic.

MATERIALS AND METHODS

Cytomorphological features of 11 cases of solid pseudopapillary neoplasm diagnosed by pre-operative fine-needle aspiration cytology (FNAC) at our institute were reviewed. Immunocytochemistry for CD 99 was also performed on the smears.

RESULTS

All the cases had cellular smears with monomorphic cells lying singly, as loosely cohesive clusters as well as forming delicate pseudopapillae. Presence of intra and extra-cellular basement membrane material, background foamy macrophages and nuclear grooves were the other salient features. Immunocytochemistry for CD 99 could be performed on eight cases and demonstrated typical paranuclear dot-like positivity.

CONCLUSIONS

Pre-operative early diagnosis of SPTP can be made by FNAC which can further be aided by CD 99 immunocytochemistry.

Endoscopic ultrasound-guided fine needle aspiration of solid pseudopapillary tumors of the pancreas: a report of three cases

The solid pseudopapillary tumor (SPT) of the pancreas is a rare but low-grade malignant tumor with a good prognosis after surgical excision. Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) is a minimally invasive, safe and reliable way of diagnosing SPT by providing characteristic cytological and immunochemical specimens. Definitive preoperative diagnosis leads to targeted and minimally invasive surgical resection. In this study, we report three cases of SPTs that were diagnosed through EUS-FNA and underwent successful laparoscopic surgery.

Two rare cases of a solid pseudopapillary neoplasm of the pancreas

A solid pseudopapillary neoplasm (SPN) of the pancreas has distinct histopathological features. A solid pattern of growth with pseudopapillary structures that result from degeneration is observed. On rare occasions, the tumor may vary from being entirely solid to completely cystic. The present study describes two unique cases of SPN. A 25-year-old male presented with a pancreatic tumor showing a predominantly solid pattern with no degenerative change, although the pre-operative cytological specimens that were obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) revealed pseudopapillary structures. The second case was of an 11-year-old female who presented with a pancreatic tumor with prominent degeneration. Nests and cords of the remaining neoplastic cells were located only at the periphery, with perineural invasion. An immunohistochemical analysis revealed that the tumor cells in the two cases were positive for CD10 and β-catenin and negative for trypsin. An awareness of the broad morphological variability of SPN and an immunohistochemical panel that includes CD10, β-catenin and trypsin are useful for establishing an accurate diagnosis.

Clinicopathologic features and surgical outcome of solid pseudopapillary tumor of the pancreas: analysis of 17 cases

BACKGROUND

We summarize our experience of the diagnosis, surgical treatment, and prognosis of solid pseudopapillary tumors (SPTs).

METHODS

We carried out a retrospective study of clinical data from a series of 17 patients with SPT managed in two hospitals between October 2001 and November 2011.

RESULTS

All of the 17 patients were female and the average age at diagnosis was 26.6 years (range 11 years to 55 years). The tumor was located in the body or tail in ten patients, the head in five patients, and the neck in two patients. The median tumor size was 5.5 cm (range 2 cm to 10 cm). All 17 patients had curative resections, including seven distal pancreatectomies, five local resections, four pancreaticoduodenectomies, and one central pancreatectomy. Two patients required concomitant splenic vein resection due to local tumor invasion. All patients were alive and disease-free at a median follow-up of 48.2 months (range 2 to 90 months). There were no significant associations between clinicopathologic factors and malignant potential of SPT. Ki-67 was detected in three patients with pancreatic parenchyma invasion.

CONCLUSIONS

The SPT is an infrequent tumor, typically affecting young women without notable symptoms. Surgical resection is justified even in the presence of local invasion or metastases, as patients demonstrate excellent long-term survival. Positive immunoreactivity for Ki-67 may predict the malignant potential of SPTs.

Three female familial cases of solid pseudopapillary tumors with a protease serine 1 gene mutation

Solid pseudopapillary tumors (SPTs) are a rare pancreatic neoplastic lesion. Familial aggregation has not been reported in this disease. The objectives of this study were to report the history, clinicopathological features, and gene mutations of 3 familial cases of SPT. Three female cases of SPT presented in 1 family. Eight family relatives, 5 healthy volunteers, and 8 patients with SPT acted as controls. Histological examination and immunohistochemistry were performed on the surgical tumor specimens. Polymerase chain reaction-single-strand conformation polymorphism and gene sequencing were performed on genomic DNA extracted from blood. All 3 patients underwent surgical treatment, 2 patients died (3 months and 5 months after surgery), whereas neither recurrence nor metastasis was observed in the other patient during 2-year follow-up. The tumors from the 3 cases had identical immunoreactivity to a series of molecular markers. A Leu104Val mutation of protease serine 1 (PRSS1) was observed in the familial patients and 2 healthy male family members; no β-catenin or adenomatous polyposis coli mutations were detected in the familial cases. This study indicates the possibility of genetic involvement in the pathogenesis of SPT. Family history may be a positive predictive factor for malignancy in SPT.

Cercariform cells: another cytologic feature distinguishing solid pseudopapillary neoplasms from pancreatic endocrine neoplasms and acinar cell carcinomas in endoscopic ultrasound-guided fine-needle aspirates

BACKGROUND

Solid pseudopapillary neoplasm (SPPN) is a rare tumor of unknown origin that occurs predominantly in the body or tail of the pancreas in young women. The authors recently identified cercariform (Greek: tailed) cells, similar to those described in urothelial carcinomas, as a consistent cytologic feature in ultrasound-guided fine-needle aspiration (EUS-FNA) samples from SPPNs. The objective of the current multi-institutional study was to define the value of these cells in the differential diagnosis of SPPN with other neoplasms characterized cytologically by the presence of monotonous, uniform cells in pancreatic aspirates: pancreatic neuroendocrine tumors (Pan-NETs) and acinar cell carcinomas (ACCs).

METHODS

The files of 4 academic hospitals were searched for SPPNs, Pan-NETs, and ACCs that were diagnosed by EUS-FNA. The slides were reviewed, and several cytologic features were recorded semiquantitatively to identify discriminating features between SPPNs, Pan-NETs, and ACCs.

RESULTS

From the analysis of 18 SPPNs, 4 ACCs, and 20 Pan-NETs, the following cytologic features were identified as common to all 3 neoplasms: single cells and rosettes/acinar cell groups, round-to-plasmacytoid cells, pale-to-granular cytoplasm, fine vacuoles, and binucleated cells. Papillary structures, cercariform cells, large cytoplasmic vacuoles, reniform nuclei, hyaline globules/magenta-colored material, and degenerative features (cholesterol crystals, calcifications, foam cells, or giant cells) were significantly more common in SPPNs. Prominent nuclear grooves were encountered in only 4 of 18 SPPNs.

CONCLUSIONS

The current results indicated that the presence of cercariform cells is another useful clue for the cytologic diagnosis of SPPN in challenging cases.

Histologic evaluation of intrahepatic micrometastases in patients treated with or without neoadjuvant chemotherapy for colorectal carcinoma liver metastasis

Solid pseudopapillary neoplasm of the pancreas (SPN) is relatively rare and it occurs almost exclusively in women. We recently experienced three cases of SPN diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). These three cases were two male and one female patient whose age was 29, 37, and 44 years old. Radiological diagnosis was pancreatic endocrine tumor (PEN) showing solid with a heterogenous echogenicity. EUS-FNA cytology specimens consisted of single cells and aggregates of uniform cells, forming microadenoid structures, branching, papillary clusters with delicate fibrovascular cores. In conclusion, a single diagnosis of SPN based on clinical and radiological findings would be risky because there is a possibility of it being misdiagnosed as PEN or other malignancies. An EUS-FNA is therefore essential for establishing the diagnosis. In addition, the pathologists should recognize the characteristic cytologic findings with immunoprofiles of SPN to prevent misdiagnosis of SPN.