Solid-pseudopapillary neoplasm of the pancreas: spectrum of findings on multidetector CT

Cinematic rendering of solid pseudopapillary tumors: Augmenting diagnostics of an increasingly encountered tumor

Pancreatic solid pseudopapillary tumors (SPTs) are a rare subset of pancreatic neoplasms, accounting for under 2 % of exocrine pancreatic tumors. The incidence of SPTs has shown a significant increase in the past two decades, attributed to heightened cross-sectional imaging utilization. These tumors often present with nonspecific clinical symptoms, making imaging a crucial tool in their detection and diagnosis. Cinematic rendering (CR) is an advanced 3D post-processing technique that generates highly photorealistic realistic images by accurately modeling the interaction of light within the imaged volume. This allows improved visualization of anatomic structures which holds potential to improve diagnostics. In this manuscript we present the first description of CR appearances of SPTs in the reported literature. Through showcasing a range of cases, we highlight the potential of CR in illustrating the diverse imaging characteristics of these unique neoplasms.

Diagnosis and surgical management of a rare neoplastic entity: Solid Pseudopapillary Neoplasm of the Pancreas

INTRODUCTION AND IMPORTANCE

Solid Pseudopapillary Tumors of the Pancreas is an extremely rare pancreatic neoplastic entity that makes up barely 3 % of all types of exocrine pancreatic neoplasia. Symptoms vary and none of them are specific or pathognomonic for the disease. Therefore, delayed treatment or misdiagnoses could be the result. In turn, patients' morbidity and mortality significantly rise. Diagnosing or suspecting this type of critical type of neoplasia in the preoperative phase is a key component to performing appropriate and curative surgical interventions that result in increased patient survivability.

CASE PRESENTATION

We hereby present the rare case of a previously healthy 20-year-old female whose chief complaints were chronic epigastric and left hypochondriac region pain and discomfort along with loss of appetite. During our preoperative radiological investigation, we found a cystic mass with well-defined borders located between the head of the pancreas and the second part of the duodenum. It measured (63 × 45 mm). No metastasis or lymph node involvement was elicited.

CLINICAL DISCUSSION

The tumor was utterly resected via a successful Whipple procedure. A definitive diagnosis of a Solid Pseudopapillary Tumor was reached following meticulous histopathological and immunohistochemical analysis of the resected specimens.

CONCLUSION

Based on our review of the published literature, no previously published cases from our country of pancreatic Solid Pseudopapillary Tumors exist. Documentation of this rare neoplasia is warranted to raise awareness and to establish the necessary clinical protocols to optimally diagnose, timely treat, and adequately follow up on patients who present with this malignancy.

Pancreatic solid pseudopapillary neoplasm with concomitant left unilateral renal agenesis and bicornuate uterus: a case report

A solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor of the pancreas. Concomitant SPN with urogenital anomalies is a very rare presentation.

Case Presentation

A 16-year-old female presented with a chief complaint of abdominal pain 30 days back. Solid pseudopapillary neoplasm (SPN) of the pancreas was diagnosed with the aid of ultrasonography and contrast-enhanced computed tomography of the abdomen and pelvis. Incidentally, concomitant left unilateral renal agenesis and bicornuate uterus were also detected in radiological findings. The patient underwent spleen-preserving distal pancreatectomy, and SPN was confirmed with the histopathological report.

Discussion

Symptomatic SPN patients present with an abdominal mass and pain or very rarely jaundice. Most of the SPNs are benign. Complete surgical excision results in more than 95% cure. SPN with concomitant urogenital anomalies is extremely rare, and their concurrent occurrence can be better attributed to Wnt signaling pathway owing to their similar pathogenic mechanism.

Conclusion

The solid pseudopapillary tumor has an excellent prognosis if timely resected. Proper evaluation of the patient with imaging is necessary to suspect and diagnose SPN who has urogenital anomalies and vice versa.

A case of middle-aged male with multicentric solid pseudopapillary neoplasm of the pancreas

Solid pseudopapillary neoplasm (SPN) of the pancreas is a low-grade, malignant pancreatic tumor that occurs predominantly in young females. In this report, an extremely rare case of multicentric SPNs in a middle-aged male is discussed. A 55-year-old man was incidentally found to have a mass in the pancreatic body on abdominal ultrasonography during a medical checkup. Contrast-enhanced computed tomography (CT) revealed masses with 50-mm and 25-mm diameters with internal calcification in the pancreatic body and tail, respectively. These masses had a gradually increasing enhancement pattern though the center of the pancreatic body mass and the periphery of the pancreatic tail lesion were non-enhancing. Magnetic resonance imaging revealed a hyperintense signal in the mass of the pancreatic tail suggestive of hemorrhage on T1-weighted imaging. Positron emission tomography-CT revealed abnormal uptake of fluorodeoxyglucose in both lesions. Endoscopic ultrasound-guided fine needle aspiration was performed on both lesions, and tumor tissue with a solid proliferation of poorly pleomorphic small cells was observed. The tumor cells were positive for CD10 in the cytoplasm and β-catenin in the nucleus. The patient was diagnosed with SPNs and underwent a successful distal pancreatectomy.

Solid Pseudopapillary Neoplasms of the Pancreas Across Races Demonstrate Disparities with Comparably Good Prognosis

BACKGROUND

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare with low-grade malignancy and unclarified clinicopathological features. This study aimed to examine their characteristics and re-evaluate current treatments.

METHODS

Databases from three sources were screened for patients with SPNs. We compared the perioperative variables, clinical data, overall survival (OS), and prognostic factors for recurrence among the three corresponding cohorts.

RESULTS

We identified 286 patients diagnosed with SPNs between 1988 and 2020. Patients were mostly women (81%; median age: 38 years), and peak incidence was observed in women of 20-29 years of age. SPNs had a peak incidence in Asian men at 50-59 years of age (p = 0.002) and a delayed peak incidence in Asian women at 30-39 years of age (p < 0.001). Treatment strategies differed significantly across the institutions and included variations in the number of harvested lymph nodes and rates of vascular resection. Lymph node positivity was the only predictor of postoperative recurrence (odds ratio, 2.2; 95% confidence interval, 1.38-2.99; p = 0.007). Higher rates of lymphovascular invasion (p = 0.02), perineural invasion (p < 0.001), and R1 margin involvement (p < 0.001), as seen in one institution, did not result in poorer long-term survival in terms of the overall (p = 0.43), SPN-specific (p = 0.69), and recurrence-free survivals (p = 0.067).

CONCLUSIONS

In contrast to previous findings that SPNs are prevalent in young women, a racial predilection for middle-aged Asian men and a delayed female peak incidence were noted. Parenchyma-preserving pancreatectomy may be an acceptable treatment. Non-radical surgery may be appropriate in patients with multiple comorbidities.

Clinical Course, Genetic, and Immunohistochemical Characterization of Solid Pseudopapillary Tumor of the Pancreas (Frantz Tumors) in a Brazilian Cohort

Frantz tumors or solid pseudopapillary pancreatic neoplasm (SPN) are rare exocrine neoplasms that carry a favorable prognosis; they represent up to 3% of all tumors located in the region of the pancreas and have specific age and gender predispositions. In recent years, the rising curve of diagnosis is entitled to the evolution and access of diagnostic imaging. In this paper, we have retrospectively reviewed and described the clinical course of 40 patients with SPN from three institutions in Brazil, who had their diagnosis between 2005 and 2020, and analyzed the clinicopathological, genetic, and surgical aspects of these individuals. In accordance with the literature, most patients were women, 60% with unspecified symptoms at diagnosis, with tumors mainly located in the body and tail of the pancreas, of whom 70% underwent a distal pancreatectomy with sparing splenectomy as a standard procedure, and none of the cases have experienced recurrence to date. Surgery still remains the mainstay of treatment given the low metastatic potential, but more conservative approaches as observed in this cohort are evolving to become the standard of care. Herein, we present an in-depth analysis of cases focusing on the latest literature and report some of the smallest tumor cases in the literature. To our knowledge, this is the first report evaluating germline genetic testing and presenting a case of detected Li-Fraumeni syndrome.

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 Neoplasms of the Pancreas: a Single-Center Experience and Review of the Literature

PURPOSE

Pancreatic solid pseudopapillary neoplasms (SPNs) are rare borderline tumours mainly affecting young female patients. The number of patients diagnosed with SPNs has increased significantly in the last decades owing to the increased use of cross-sectional imaging investigating different abdominal symptoms, whilst a significant proportion are incidentally discovered during the process of evaluating other pathologies. We herein present our institutional experience of patients with SPN who underwent curative resection focusing on clinical, pathological features, and the long-term outcomes.

METHODS

All patients undergoing pancreatectomy in our institution for SPN from January 2010 until December 2018 were included. Clinical, perioperative, histological, and long-term outcomes were collected and analysed.

RESULTS

During the inclusion period, a total of 19 patients had a pathological diagnosis of SPNs after surgical resection. Sixteen of them were female (84%), while the median patient age was 30 (range 16-66) years. Nine patients (47%) underwent distal pancreatectomy and splenectomy, 2 (11%) underwent spleen preserving distal pancreatectomy, 6 (32%) underwent pancreatoduodenectomy, one (5%) underwent total pancreatectomy, and one (5%) central pancreatectomy. Seventeen patients underwent R0 resection. During a median follow-up of 23 months, no tumour recurrence or death was recorded.

CONCLUSION

In our experience, SPNs are rare tumours with low malignant potentials. Surgical resection remains the gold standard treatment and is associated with good prognosis.

Surgical Resection of 78 Pancreatic Solid Pseudopapillary Tumors: a 30-Year Single Institutional Experience

BACKGROUND

Solid pseudopapillary tumors (SPTs) are rare, benign tumors of the pancreas that present as heterogeneous masses. We sought to evaluate the short- and long-term outcomes of surgical resected SPTs. Patients managed via initial surveillance were compared to those who underwent upfront resection.

METHODS

A prospectively maintained institutional database was used to identify patients who underwent surgical resection for a SPT between 1988 and 2018. Data on clinicopathological features and outcomes were collected and analyzed.

RESULTS

Seventy-eight patients underwent surgical resection for SPT during the study period. The mean age was 34.0 ± 14.6 years and a majority were female (N = 67, 85.9%) and white (N = 46, 58.9%). Thirty patients (37.9%) were diagnosed incidentally. Imaging-based presumed diagnosis was SPT in 49 patients (62.8%). A majority were located in the body or tail of the pancreas (N = 47, 60.3%), and 48 patients (61.5%) underwent a distal pancreatectomy. The median tumor size was 4.0 cm (IQR, 3.0-6.0), nodal disease was present in three patients (3.9%), and R0 resection was performed in all patients. No difference was observed in clinicopathological features and outcomes between patients who were initially managed via surveillance and those who underwent upfront resection. None of the patients under surveillance had nodal disease or metastasis at the time of resection; however, one of them developed recurrence of disease 95.1 months after resection. At a median follow-up of 36.1 months (IQR, 8.1-62.1), 77 (%) patients were alive and one patient (1.3%) had a recurrence of disease at 95.1 months after resection and subsequently died due to disease.

CONCLUSIONS

SPTs are rare pancreatic tumors that are diagnosed most frequently in young females. While a majority are benign and have an indolent course, malignant behavior has been observed. Surgical resection can result in exceptional outcomes.

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

OBJECTIVE

The aim of this study was to evaluate the clinicopathological features of solid pseudopapillary neoplasms (SPNs).

METHODS

In this retrospective study, 288 SPNs were analyzed.

RESULTS

Overall, 214 patients (74%) were female. Distant metastases occurred in 4 patients, and splenic vein tumor thrombus occurred in 1 patient. Although imaging findings showed large (>2.0 cm) SPNs with clear, regular border, and heterogeneous internal structure, small SPNs appeared as almost entirely solid. Surgical resection was performed in 278 cases. The 5-year survival rate was 98.8%. Six patients had tumor recurrence after the initial resection. The detection rate in typical pathological findings was low for small SPNs. Tumor extension to the pancreatic parenchyma was detected in greater than 70% of the cases. Tumor invasion to adjacent organs was detected in 13 cases. One was given a diagnosis of apparent high-grade malignant transformation.

CONCLUSIONS

The proportion of male cases was higher than that in previous studies, and there were statistically significant differences in the onset age and tumor diameter between male and female patients. Therefore, women seemed to have an early occurrence of SPNs, suggesting a difference in the developmental stage between men and women. Images and pathological findings of SPNs varied according to tumor size. Our findings indicated that SPN patients have excellent survival after margin-negative surgical resection.

Does Computed Tomography Have the Ability to Differentiate Aggressive From Nonaggressive Solid Pseudopapillary Neoplasm?

OBJECTIVE

The aim of the study was to assess the ability of contrast-enhanced computed tomography (CECT) to differentiate aggressive from nonaggressive solid pseudopapillary neoplasms (SPNs).

MATERIALS AND METHODS

Forty treatment-naive patients with pathologically proven pancreatic SPNs were included. Imaging characteristics were determined by consensus of 3 radiologists blinded to histopathologic aggressiveness. All patients underwent 4-phase CECT using a pancreatic protocol. The regions of interest of the tumor and the normal pancreas were documented on all phases. Lymph nodes were considered metastatic if greater than 1.0 cm in short-axis diameter.Fisher exact and Wilcoxon rank-sum tests were used to compare between aggressive and nonaggressive tumors.

RESULTS

No significant difference was noted between imaging covariates, such as internal hemorrhage, calcification, wall thickness perceptibility, vascular invasion, margins, cystic component, and pancreatic and biliary ductal dilation. Tumors with greater than 62.5 Hounsfield units and progressive enhancement during the delayed phase had aggressive characteristics (P = 0.03).

CONCLUSIONS

On delayed phase CECT, pathologically aggressive SPNs may show greater enhancement than nonaggressive SPNs.

Solid Pseudopapillary Neoplasm of the Pancreas: A Rare Entity With Unique Features

Solid pseudopapillary neoplasm of the pancreas is a rare entity with low malignant potential and excellent overall prognosis. It has nonspecific clinical presentations such as abdominal pain and nausea, with vague radiologic features. Histologic features of this neoplasm are usually specific. The tumor shows minimally cohesive, uniform, monotonous cells lining delicate capillary-sized blood vessels, described as pseudopapillary architecture. Other features including hyaline globules, cytoplasmic vacuoles, and nuclear grooving are frequently present. Use of a select panel of immunostains always helps pathologists to differentiate this tumor from other circumscribed tumors of the pancreas. Recently, β-catenin, CD10, and E-cadherin have been shown to be very important in the diagnosis of solid pseudopapillary neoplasm. Nuclear staining of tumor cells by β-catenin and membranous presentation of CD10 is seen in almost 100% of cases. Tumor cells can be partially positive for synaptophysin and chromogranin. This tumor has a low malignant potential, and definite treatment is surgical resection.

A distinctive myoepithelial hamartoma of the pancreas histologically confirmed in the mother of a previously reported patient

We encountered a 62-year-old female patient with a distinctive pancreatic myoepithelial hamartoma characterized by dilated loops formed by pancreatic branch ducts. The patient, who experienced recurrent acute pancreatitis caused by pancreatic juice stasis, underwent subtotal stomach-preserving pancreatoduodenectomy, achieving remission of pancreatitis. Computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) demonstrated a honeycomb appearance of the pancreatic head, consisting largely of loop-forming dilated pancreatic branch ducts. Radiography of resected specimens demonstrated a tortuous main pancreatic duct that narrowed in the head, but communicated with the pancreatic branch ducts forming intricate loops within the lesion. Histologic examination showed dilated pancreatic ducts embedded in thick layers of smooth muscle, leading to a diagnosis of myoepithelial hamartoma. Her son shared a similar clinical course, radiologic findings, and histopathologic findings with his mother. MRCP demonstrated a honeycomb appearance of the pancreatic head in her daughter, who complained of persistent diarrhea. To our knowledge, this is the first English-language reports of such a myoepithelial hamartoma of the pancreas showing familial occurrence.

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.

Solid Pseudopapillary Neoplasms of the Pancreas: a 19-Year Multicenter Experience in China

AIM

The aim of this study was to determine the clinicopathological features, surgical management, and prognosis of solid pseudopapillary neoplasms (SPNs) of the pancreas.

METHODS

This study conducted a retrospective analysis of 97 patients who underwent surgery for a pathologically confirmed SPN in five hospitals between January 1996 and December 2014.

RESULTS

The 97 cases included 93 female and 4 male patients, and the average age was 31.2 years. The tumor was located in the body or tail (70.1%), the head (20.6%), and the neck (9.3%). All patients underwent surgical exploration, including distal pancreatectomy (63.9%), pancreaticoduodenectomy (20.6%) (partial portal vein or superior mesenteric vein resection and artificial vascular graft reconstruction performed in 4.1% of the patients), central pancreatectomy (10.3%), enucleation (5.2%), and liver resection (1.0%). 16.5% of the patients had malignant tumors. The positive rate of Ki-67 was 66.7% in patients diagnosed with a malignant neoplasm and was comparable to 8.4% of the patients diagnosed to have a benign neoplasm (p < 0.001). After a median follow-up of 70.1 months, three patients had recurrence and one patient died of liver metastasis.

CONCLUSIONS

SPN is a rare neoplasm with low malignant potential. Surgical resection is warranted 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 and poor outcome of SPNs.

Pathological features and diagnosis of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a noninvasive epithelial neoplasm of mucin-producing cells arising in the main duct (MD) and/or branch ducts (BD) of the pancreas. Involved ducts are dilated and filled with neoplastic papillae and mucus in variable intensity. IPMN lacks ovarian-type stroma, unlike mucinous cystic neoplasm, and is defined as a grossly visible entity (≥ 5 mm), unlike pancreatic intraepithelial neoplasm. With the use of high-resolution imaging techniques, very small IPMNs are increasingly being identified. Most IPMNs are solitary and located in the pancreatic head, although 20%-40% are multifocal. Macroscopic classification in MD type, BD type and mixed or combined type reflects biological differences with important prognostic and preoperative clinical management implications. Based on cytoarchitectural atypia, IPMN is classified into low-grade, intermediate-grade and high-grade dysplasia. Based on histological features and mucin (MUC) immunophenotype, IPMNs are classified into gastric, intestinal, pancreatobiliary and oncocytic types. These different phenotypes can be observed together, with the IPMN classified according to the predominant type. Two pathways have been suggested: gastric phenotype corresponds to less aggressive uncommitted cells (MUC1 -, MUC2 -, MUC5AC +, MUC6 +) with the capacity to evolve to intestinal phenotype (intestinal pathway) (MUC1 -, MUC2 +, MUC5AC +, MUC6 - or weak +) or pancreatobiliary /oncocytic phenotypes (pyloropancreatic pathway) (MUC1 +, MUC 2-, MUC5AC +, MUC 6 +) becoming more aggressive. Prognosis of IPMN is excellent but critically worsens when invasive carcinoma arises (about 40% of IPMNs), except in some cases of minimal invasion. The clinical challenge is to establish which IPMNs should be removed because of their higher risk of developing invasive cancer. Once resected, they must be extensively sampled or, much better, submitted in its entirety for microscopic study to completely rule out associated invasive carcinoma.

Solid-pseudopapillary tumor of the pancreas: MR imaging findings in 21 patients

PURPOSE

Solid-pseudopapillary tumor (SPT) of the pancreas is a rare, low-grade malignancy, which mostly occurs in adolescent and young adult females. The goal of this study was to retrospectively analyze the magnetic resonance (MR) imaging presentation of SPT of the pancreas.

METHODS

We retrospectively reviewed the preoperative MR imaging examinations and the medical, surgical and histopathological records of 21 patients who underwent surgery for SPT of the pancreas. MR imaging included T1-weighted, T2-weighted, and gadolinium chelate-enhanced MR imaging. In addition, 10 patients had diffusion-weighted (DW) MR imaging. MR examinations were retrospectively reviewed for location, size, morphological features and signal intensity of the tumors.

RESULTS

Nineteen women and 2 men (median age, 23 years; range, 14-59) were included. Seven patients (7/21; 33%) presented with abdominal symptoms. The median largest tumor diameter was 53mm (range, 32-141 mm). SPTs were located in the pancreatic head, body, and tail in 9 (9/21; 43%), 5 (5/21; 24%) and 7 (7/21, 33%) patients, respectively. All patients (21/21; 100%) had a single SPT. SPTs were more frequently oval (12/21; 57%), predominantly solid (12/21; 57%), fully encapsulated (16/21; 76%), larger than 30 mm (21/21; 100%), hypointense on T1-weighted MR images (21/21, 100%), hyperintense on T2-weighted MR images (21/21; 100%) and with an enhancing capsule after gadolinium-chelate administration (21/21; 100%).

CONCLUSIONS

There is trend of appearance for SPT of the pancreas on MR imaging but that variations may be observed in a number of cases. SPT uniformly presents as a single, well-demarcated and encapsulated pancreatic mass.

Institutional experience with solid pseudopapillary neoplasms: focus on computed tomography, magnetic resonance imaging, conventional ultrasound, endoscopic ultrasound, and predictors of aggressive histology

OBJECTIVE

Solid pseudopapillary neoplasms (SPNs) are low-grade malignancies with an excellent prognosis, albeit with the potential for metastatic disease. This study details our institution's experience with the diagnosis and treatment of SPN, including clinical presentation, multimodality imaging findings, and potential predictors of aggressive tumor behavior.

MATERIALS AND METHODS

The institutional pathology database was searched through for all cases of SPN since 1988, yielding 51 patients. The electronic medical record was searched for clinical and demographic information regarding these patients, including age, sex, presenting symptoms, type of surgery, postoperative length of stay, tumor markers, and postsurgical follow-up. All available imaging data were reviewed, including those of 30 patients who underwent multidetector computed tomography, those of 9 patients who underwent magnetic resonance imaging (MRI), those of 3 patients who underwent conventional ultrasound, and those of 11 patients who underwent endoscopic ultrasound.

RESULTS

A total of 84% of patients were females, with a mean age of only 33 years. Prognosis was excellent, with a mean follow-up of 3 years without recurrence. Only 1 of the 51 patients developed metastatic disease to the liver 8 years after the surgery. On computed tomography, lesions tended to be large (5.3 cm), well circumscribed (29/30), round/oval (20/30), and encapsulated (23/30). The lesions often demonstrated calcification (14/30) and typically resulted in no biliary or pancreatic ductal dilatation. The lesions ranged from completely cystic to completely solid. On MRI, the lesions often demonstrated a T2 hypointense or enhancing capsule (6/9) and demonstrated internal blood products (5/9). The lesions tended to be devoid of vascularity on conventional ultrasound. Ten patients were found to have "aggressive" histology at presentation (T3 tumor, nodal involvement, perineural invasion, or vascular invasion). No demographic, clinical, or multidetector computed tomographic imaging features were found to correlate with aggressive histology.

CONCLUSIONS

Certain imaging features (eg, well-circumscribed mass with calcification, peripheral capsule, internal blood products, and lack of biliary/pancreatic ductal obstruction) on computed tomography and MRI are highly suggestive of the diagnosis of SPN, particularly when visualized in young female patients. However, it is not possible to predict aggressive histology on the basis of imaging findings, clinical presentation, or patient demographic features.

Diagnostic value of ultrasound in detection of solid pseudopapillary tumor of the pancreas

AIM: To investigate the diagnostic value of ultrasound in the detection of solid pseudopapillary tumor of the pancreas (SPTs).

METHODS: The data of ultrasound and contrast-enhanced ultrasound for 30 patients with pathologically confirmed SPTs were retrospectively analyzed. The rates of detection of SPTs by the two methods were compared using the χ² test or Fisher's exact test.

RESULTS: Of 30 patients, 1 was male and the others were female. Their mean age was 30.5 years, ranging from 13 to 58 years. Fourteen tumors were located in the head of the pancreas, 4 in the body of the pancreas and 12 in the tail of the pancreas. The size of tumors ranged from 1.5 cm × 1.1 cm × 1.8 cm to 21 cm × 11 cm × 15 cm. Of 26 cases examined by ultrasound, 17 were correctly diagnosed, 1 had missed diagnosis, and 8 were diagnosed with other tumors of the pancreas. Of 4 cases examined by contrast-enhanced ultrasonography, 3 were correctly diagnosed and 1 was diagnosed with other tumor of the pancreas. There was no significant difference in the diagnostic accuracy between the two methods (64% vs 75%, P = 0.593).

CONCLUSION: SPTs exhibit some special ultrasound features, which may be helpful to diagnose this type of tumor.

miRNA biomarkers in cyst fluid augment the diagnosis and management of pancreatic cysts

PURPOSE

The diagnosis of pancreatic cystic lesions has increased dramatically. Most are benign, whereas some, such as intraductal papillary mucinous neoplasms (IPMN), represent precursors of pancreatic adenocarcinoma. Therapeutic stratification of IPMNs is challenging without precise information on dysplasia grade and presence of invasion. We assessed the diagnostic benefit of using miRNAs as biomarkers in pancreatic cyst fluid, focusing on IPMNs because of their frequency and malignant potential.

EXPERIMENTAL DESIGN

RNA was extracted from 55 microdissected formalin-fixed, paraffin-embedded (FFPE) IPMN specimens, and 65 cyst fluid specimens aspirated following surgical resection. Expression of 750 miRNAs was evaluated with TaqMan miRNA Arrays using 22 FFPE and 15 cyst fluid specimens. Differential expression of selected miRNA candidates was validated in 33 FFPE and 50 cyst fluid specimens using TaqMan miRNA Assays.

RESULTS

We identified 26 and 37 candidate miRNAs that distinguish low-grade from high-grade IPMNs using FFPE and cyst fluid specimens, respectively. A subset of 18 miRNAs, selected from FFPE and cyst fluid data, separated high-grade IPMNs from low-grade IPMNs, serous cystadenomas (SCA) and uncommon cysts, such as solid pseudopapillary neoplasms (SPN) and cystic pancreatic neuroendocrine tumors (PanNET). A logistic regression model using nine miRNAs allowed prediction of cyst pathology implying resection (high-grade IPMNs, PanNETs, and SPNs) versus conservative management (low-grade IPMNs, SCAs), with a sensitivity of 89%, a specificity of 100%, and area under the curve of 1.

CONCLUSIONS

We found candidate miRNAs that helped identify patients with high-grade IPMN and exclude nonmucinous cysts. These classifiers will require validation in a prospective setting to ultimately confirm their clinical usefulness.

Differentiation between benign and malignant solid pseudopapillary tumor of the pancreas by MDCT

PURPOSE

The purpose of this study was to determine if characteristic features on computed tomographic and (or) magnetic resonance imaging can differentiate benign and malignant solid pseudopapillary neoplasms (SPN).

MATERIALS AND METHODS

A total of 82 pathologically diagnosed SPN patients were included. CT and MRI were reviewed by 3 radiologists. Each tumor was analyzed through the clinical and imaging features.

RESULTS

The highest occurrence of malignant SPN was observed in the group of patients (11-19 years old) followed by the group of patients (50-65 years old). When the tumor was located in the tail and the size was equal or larger than 6.0 cm, the positive and predictive value, the predictive value, sensitivity and specificity for a malignant SPN were 61.5%, 100%, 100% and 78.6%, respectively. Presence of complete encapsulation was more frequent in benign SPNs, but focal discontinuity in the malignant SPNs. Amorphous or scattered calcifications, all near-solid tumors and presence of upstream pancreatic ductal was found in the benign SPNs.

CONCLUSION

A focal discontinuity of the capsule, large tumor size (>6.0 cm) and a pancreatic tail location may suggest malignancy of SPN. In contrast, tumors with amorphous or scattered calcifications, and all near-solid tumors may be indicative of benignancy. Age (less than 20 or more than 50 years old) is a possible risk factor of SPN. In comparison to other pancreatic neoplasms, such as ductal adenocarcinoma, a complete/incomplete pseudo-capsule, without upstream pancreatic duct dilatation and lymph nodes metastasis, and the presence of internal calcification and hemorrhage are more likely SPN.

Solid pseudopapillary tumors of the pancreas: contrast-enhanced sonographic features

OBJECTIVES

The aims of this study were to determine the features of solid pseudopapillary tumors of the pancreas on contrast-enhanced sonography and correlate them with pathologic findings.

METHODS

Five patients with solid pseudopapillary tumors of the pancreas underwent conventional sonographic, color Doppler flow imaging, and contrast-enhanced sonographic examinations. Time-intensity curves were used to calculate the contrast enhancement times, wash-out times, and enhancement patterns of the lesions. Three of the 5 patients also underwent contrast-enhanced computed tomography. All cases were confirmed by surgery and pathologic examination.

RESULTS

The study included 3 women and 2 men. Tumor diameters ranged from 4.4 to 13.0 cm. Sonography revealed round well-defined encapsulated tumors. Two appeared as mixed cystic-solid and 3 as solid masses on conventional sonography. One mass had a macrocalcification. Some areas of blood flow were seen in 3 of the masses on color Doppler flow imaging. On contrast-enhanced sonography, the peripheral rims of the tumors showed isoenhancement during the early arterial phase, and the interiors of the masses showed heterogeneous enhancement consisting of regions of isoenhancement, hypoenhancement, and nonenhancement. Progressive wash-out of the contrast agent during venous phases revealed hypoenhancement compared with normal adjacent pancreatic parenchyma. Pathologic findings showed that each tumor was completely encapsulated and had varying degrees of internal hemorrhage and necrosis.

CONCLUSIONS

Solid pseudopapillary tumors of the pancreas have characteristic findings on contrast-enhanced sonography, including peripheral rim isoenhancement and internal heterogeneous enhancement with nonenhanced portions; these features may help differentiate solid pseudopapillary tumors from other pancreatic neoplasms.

Diagnosis and management of cystic lesions of the pancreas

Pancreatic cysts are challenging lesions to diagnose and to treat. Determining which of the five most common diagnoses—pancreatic pseudocyst, serous cystic neoplasm (SCN), solid pseudopapillary neoplasm (SPN), mucinous cystic neoplasm (MCN), and intraductal mucinous papillary neoplasm (IPMN)—is likely the correct one requires the careful integration of many historical, radiographic, laboratory, and other factors, and management is markedly different depending on the type of cystic lesion of the pancreas. Pseudocysts are generally distinguishable based on historical, clinical and radiographic characteristics, and among the others, the most important differentiation is between the mucin-producing MCN and IPMN (high risk for cancer) versus the serous SCN and SPN (low risk for cancer). EUS with FNA and cyst-fluid analysis will continue to play an important role in diagnosis. Among mucinous lesions, those that require treatment (resection currently) are any MCN, any MD IPMN, and BD IPMN larger than 3 cm, symptomatic, or with an associated mass, with the understanding that SCN or pseudocysts may be removed inadvertently due to diagnostic inaccuracy, and that a certain proportion of SPN will indeed be malignant at the time of removal. The role of ethanol ablation is under investigation as an alternative to resection in selected patients.