Diagnosis of pancreatic solid pseudopapillary neoplasms using cell‐blocks and immunohistochemical evaluation of endoscopic ultrasound‐guided fine needle aspiration biopsy specimens

Role of endoscopic ultrasound-guided fine needle aspiration biopsies in diagnosing pancreatic neoplasms in the paediatric population: experience from a tertiary center and review of the literature

BACKGROUND

Endoscopic ultrasound-guided fine needle aspiration biopsy (EUS FNAB) is a well established diagnostic method in adult patients, but is rarely used in the paediatric population. The Clinical Department of Gastroenterology at the University Clinical Centre Ljubljana and the Department of Cytopathology at the Institute of Pathology, Faculty of Medicine, University of Ljubljana, Slovenia, have been closely collaborating on EUS FNAB since the introduction in 2010. The aim of the study was to review the cases of EUS FNAB of pancreatic neoplasms in children.

PATIENTS AND METHODS

In the digital archive of the Institute of Pathology (IP), Faculty of Medicine (FM), University of Ljubljana (UL), we found 6 cases of EUS FNAB in children, 3 had EUS FNAB of the pancreas, 2 of whom had a cytopathologic diagnosis of a tumour. In the first case, the lesion was ultrasonographically solid, and the cell sample contained branching papillary structures surrounded by aggregates of small cells with nuclear grooves. In the second case, the lesion was ultrasonographically cystic, and predominantly necrosis was seen, with only single preserved cells. Positive nuclear reaction for β-catenin was found in both cases by immunohistochemical staining.

RESULTS

In both cases, the cytopathological diagnosis of solid pseudopapillary neoplasm of the pancreas was made, the cases represent the totality of paediatric cases of pancreatic neoplasms from the Children's Hospital Ljubljana since 2010. There were no adverse events during and after EUS FNAB. A histopathological examination of the tumour resection specimens confirmed the cytopathological diagnosis.

CONCLUSIONS

Our experience indicates that EUS FNAB is a safe and effective method for diagnosing pancreatic neoplasms in the pediatric population, as supported by the findings in the literature.

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

OBJECTIVES

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has been the most common method used for the preoperative cytopathological diagnosis of solid tumors of the pancreas. There are only a few reported cases about the role of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) in the pre-operative diagnosis of solid pseudopapillary neoplasms (SPN). This study aimed to evaluate the diagnostic yield of EUS-TA,including endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) andEUS-FNB, in patients with SPN.

METHODS

We performed a retrospective analysis of patients with EUS-TA for SPN diagnosis in 2 referral centers. The primary outcome was the diagnostic yield of EUS-TA compared to the surgical specimen.

RESULTS

Seventy-four patients with SPN of the pancreas were identified. Eighteen had a EUS-TA (10 EUS-FNB and 8 EUS-FNA). The median age of the patients was 31 years (IQR 21-38), and all patients were women. The most common presenting symptom was abdominal pain. Most of the tumors were in the head of the pancreas (9/18; 50%). The median tumor size by EUS was 4.5 cm (min-max 2-15 cm). The most common appearance on EUS was a solid lesion (n = 8/18, 44.4%). A definitive presurgical cytopathological diagnosis was obtained in 16/18 patients (88.8%) with EUS-TA. The sensitivity and positive predictive value of the EUS-TA were 94% each. One patient in the EUS-FNB group developed mild acute pancreatitis.

CONCLUSION

The diagnostic yield of the EUS-TA in SPN is high. In most cases, the diagnosis was obtained with the first procedure. No differences in the diagnostic yield or AEs between EUS-FNA vs. EUS-FNB needles were seen.

Solid Pseudopapillary Neoplasm of the Pancreas: A Multi-Institution Study of 118 Cases

OBJECTIVES

The aim of the study is to summary the clinicopathological characteristics and surgical outcomes of solid pseudopapillary neoplasm (SPN) of the pancreas.

METHODS

In this retrospective study, the information of 118 patients with SPN from 3 hospitals were analyzed.

RESULTS

A total of 118 patients. The mean age was 30.8 (standard deviation, 14.7) years and the majority were female (n = 95, 80.5%). Sixty-seven patients (56.8%) had clinical symptoms, of which the most common symptom was abdominal pain (49.6%). The mean tumor size was 5.9 (standard deviation, 2.9) cm. Pseudopapillary architecture was the commonest histologic feature, and β-catenin, CD56, vimentin, neuron-specific enolase, CD10, a1-antitrypsin, cytokeratins showed different degrees of positive expression in immunohistochemical staining. Fourteen patients (11.9%) presented aggressive pathologic behavior, which was correlated to the incomplete tumor capsule. At a median follow-up of 59.2 months, the recurrence rate was 1.8% and the overall 5-year survival rate was 97.7%.

CONCLUSIONS

Solid pseudopapillary neoplasm of the pancreas is a potentially low-grade malignant tumor that most frequently found in young females. Its clinical manifestations are nonspecific and the diagnosis mostly depends on pathological examination. Surgical resection is the first choice of treatment for SPN with a good prognosis.

Differential diagnosis between pancreatic solid pseudopapillary tumors and pancreatic neuroendocrine tumors based on contrast enhanced ultrasound imaging features

PURPOSES

To evaluate the application of contrast enhanced ultrasound (CEUS) in preoperatively differential diagnosis between pancreatic solid pseudopapillary tumors (SPTs) and pancreatic neuroendocrine tumors (pNETs).

PATIENTS AND METHODS

This retrospective study was approved by Institutional Review Board. Patients with surgical resection and histopathological diagnosis as SPTs and pNETs were included. All patients underwent B mode ultrasound (BMUS) and CEUS examinations within one week before surgical operation. On BMUS, the size, location, echogenicity, calcification, and margin of lesions were observed and recorded. On CEUS imaging, enhancement patterns, and enhancement degrees were recorded and analyzed. An independent t-test or Mann-Whitney U test was used for comparison between continuous variables. Chi-square test was used to compare the CEUS patterns.

RESULTS

From February 2017 to Dec 2022, patients diagnosed as SPTs (n = 39) and pNETs (n = 48) were retrospectively included. On BMUS, anechoic cystic changes (19/39, 48.72%) and hyperechoic calcification (14/39, 35.90%) are more commonly detected in SPTs (P = 0.000). On CEUS imaging, the majority of SPTs (27/39, 69.23%) showed hypo-enhancement in the arterial phase, while most of the pNETs (36/48, 75.00%) showed hyper- or iso-enhancement in the arterial phase (P = 0.000). In the venous phase, most of the SPTs (32/39, 82.05%) showed hypo-enhancement, while over half of pNETs (29/48, 60.42%) showed hyper- or iso-enhancement compared to pancreatic parenchyma (P = 0.001).

CONCLUSIONS

CEUS is a valuable and non-invasive imaging method to make preoperatively differential diagnoses between SPTs and pNETs.

Pancreatic Incidentaloma

Pancreatic incidentalomas (PIs) represent a clinical entity increasingly recognized due to advances in and easier access to imaging techniques. By definition, PIs should be detected during abdominal imaging performed for indications other than a pancreatic disease. They range from small cysts to invasive cancer. The incidental diagnosis of pancreatic cancer can contribute to early diagnosis and treatment. On the other hand, inadequate management of PIs may result in overtreatment and unneeded morbidity. Therefore, there is a strong need to evaluate the nature and clinical features of individual PIs. In this review, we summarize the major characteristics related to PIs and present suggestions for their management.

Solid Pseudopapillary Neoplasm of the Pancreas: Unfolding an Intriguing Condition

Pancreatic cancer is one of the most lethal malignant neoplasms, with a 1-year survival rate after diagnosis of 24%, and a 5-year survival rate of only 9%. While this illustrates the behavior of its main histologic type - ductal adenocarcinoma, there are other histologic subtypes of pancreatic cancer that can harbor excellent prognosis. Solid pseudopapillary neoplasm, described as a rare low-grade malignant neoplasm by the World Health Organization, is the best example of that, having an overall 5-year survival rate of about 97%. Not only the prognosis, but everything about this entity is unique: its histogenesis, epidemiology, presentation, imaging characteristics, cytology features, immunohistochemical profile, and treatment. This explains the urge to improve our understanding about this entity and thus our ability to accurately recognize and manage it. Having this in mind, this article aims to summarize the most relevant topics regarding this entity.

The Utility of Endoscopic-Ultrasonography-Guided Tissue Acquisition for Solid Pancreatic Lesions

Endoscopic-ultrasonography-guided tissue acquisition (EUS-TA) has been widely performed for the definitive diagnosis of solid pancreatic lesions (SPLs). As the puncture needles, puncture techniques, and sample processing methods have improved, EUS-TA has shown higher diagnostic yields and safety. Recently, several therapeutic target genomic biomarkers have been clarified in pancreatic ductal carcinoma (PDAC). Although only a small proportion of patients with PDAC can benefit from precision medicine based on gene mutations at present, precision medicine will also be further developed for SPLs as more therapeutic target genomic biomarkers are identified. Advances in next-generation sequencing (NGS) techniques enable the examination of multiple genetic mutations in limited tissue samples. EUS-TA is also useful for NGS and will play a more important role in determining treatment strategies. In this review, we describe the utility of EUS-TA for SPLs.

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 pancreas

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

Solid-Pseudopapillary Neoplasm of the Pancreas: A 63-Case Analysis of Clinicopathologic and Immunohistochemical Features and Risk Factors of Malignancy

Purpose

Solid-pseudopapillary neoplasm (SPN) of the pancreas, a rare tumor, has low malignant potential. However, some patients develop metastasis and recurrence after resection, with aggressive biological behaviors. This study aimed to explore the features and risk factors associated with the aggressive biological behaviors of SPNs.

Patients and Methods

We retrospectively analyzed the clinicopathological and long-term follow-up data of 63 patients diagnosed with SPN at the First Affiliated Hospital of Bengbu Medical College between January 2007 and February 2019.

Results

Sixty-three patients presented atypical clinical symptoms. The median tumor size was 7.0 cm (range, 2.4–17 cm), and imaging features were solid and cystic or solid tumors with uneven density. Frequent and diffuse nuclear LEF1 protein expression (94.2%) was observed with LEF1 having a higher sensitivity and specificity. Overall survival significantly correlated with tumor size, Ki-67 index, and lymph node metastasis (P < 0.05).

Conclusion

SPN is a rare low-grade malignancy with a specific pseudopapillary structure. LEF1 is an effective biomarker of SPNs. Although SPNs generally display indolent biological behavior, a large tumor size, high proliferation index, and lymph node metastasis may be risk factors for the aggressive behavior and poor prognosis of SPN.

Role of Endoscopic Ultrasound in the Diagnosis of Pancreatic Neuroendocrine Neoplasms

Although pancreatic neuroendocrine neoplasms (PNENs) are relatively rare tumors, their number is increasing with advances in diagnostic imaging modalities. Even small lesions that are difficult to detect using computed tomography or magnetic resonance imaging can now be detected with endoscopic ultrasound (EUS). Contrast-enhanced EUS is useful, and not only diagnosis but also malignancy detection has become possible by evaluating the vascularity of tumors. Pathological diagnosis using EUS with fine-needle aspiration (EUS-FNA) is useful when diagnostic imaging is difficult. EUS-FNA can also be used to evaluate the grade of malignancy. Pooling the data of the studies that compared the PNENs grading between EUS-FNA samples and surgical specimens showed a concordance rate of 77.5% (κ-statistic = 0.65, 95% confidence interval = 0.59–0.71, p < 0.01). Stratified analysis for small tumor size (2 cm) showed that the concordance rate was 84.5% and the kappa correlation index was 0.59 (95% confidence interval = 0.43–0.74, p < 0.01). The evolution of ultrasound imaging technologies such as contrast-enhanced and elastography and the artificial intelligence that analyzes them, the evolution of needles, and genetic analysis, will further develop the diagnosis and treatment of PNENs in the future.