Imaging features of pancreatic tumors in children: 13-year experience at a pediatric tertiary hospital

Comparison between pancreatoblastoma (PB) and solid pseudopapillary neoplasm (SPN) in pediatric patients with enhanced CT

RATIONALE AND OBJECTIVES

To investigate whether computed tomography features can differentiate pancreatoblastoma (PB) from solid pseudopapillary tumor (SPN) in children.

MATERIALS AND METHODS

Clinical and imaging data of 18 cases of PB and 61 cases of SPN confirmed by surgery or biopsy were retrospectively analyzed. All enrolled patients underwent 3 phases (non-contrast, arterial, and portal venous phases) of CT scanning. Qualitative CT analysis (location, margin, solid/cystic component proportion, calcification, hemorrhage, peritumoral vascularity, bile duct dilatation, pancreatic duct dilatation, pancreatic atrophy, vascular invasion, peripancreatic invasion, and distant metastases) and quantitative analysis (maximum tumor diameter, interface between tumor and parenchyma [delta], arterial enhancement ratio [AER], and portal enhancement ratio [PER]) were performed. The general CT morphologic features, age and tumor markers were compared also compared between the groups. Univariate analysis and the F test were conducted to identify features of PB. Then logistic Regression classifier was trained using the top five features with the highest F-value. Moreover, we used 5-fold cross-validation techniques for the validation of our model.

RESULTS

PB exhibited a significantly higher frequency of location in the body/tail, larger tumor size, poorly defined margins, calcification, peritumoral vascularity, pancreatic atrophy, and less hemorrhage. In addition, PB had higher AER, PER and lower delta relative to SPN (p < 0.05). PB presented a younger age and higher levels of AFP. Results of the F test indicated that AFP, AER, Age, calcification and pancreatic atrophy were the top five features included in the model that could differentiate pediatric PB from SPN. The combined model of CT and clinical features performed well in differentiating PB from SPN, with an AUC of 0.981 in the training cohort and 0.953 in the validation cohort.

CONCLUSIONS

AFP, AER, age, calcification and pancreatic atrophy are robust CT and clinical features for differentiating pediatric PB from SPN. A combination of qualitative and quantitative CT features may provide good diagnostic accuracy in differentiating PB from SPN in children.

Solid Pseudopapillary Epithelial Neoplasm of the Pancreas in the Paediatric Population: A Report of Two Cases

A rare pathology, the solid pseudopapillary epithelial neoplasm (SPEN) of the pancreas accounts for approximately 1% of pancreatic neoplasms. Initially called ‘Frantz’s tumour’, it has now been renamed to SPEN by the World Health Organization (WHO). This tumour has a predilection for females and a good prognosis with surgical excision being the treatment of choice.

Palpable abdominal masses in children are of significant clinical importance. Identifying cystic lesions in the pancreas from CT or MRI scans always warrant further investigations. Primary pancreatic neoplasms account for 0.1% of pancreatic tumours in the paediatric population; an extremely rare circumstance constituting a diagnostic and therapeutic challenge to surgeons. This article comprises two paediatric cases of SPEN in 14- and 11-year-old females, respectively, and a literature review on current management.

Solid pancreatic masses in children: A review of current evidence and clinical challenges

Pancreatic tumors in children are infrequently encountered in clinical practice. Their non-specific clinical presentation and overlapping imaging characteristics often make an accurate preoperative diagnosis difficult. Tumors are categorized as epithelial or non-epithelial, with epithelial tumors further classified as tumors of the exocrine or endocrine pancreas. Although both are tumors of the exocrine pancreas, solid pseudopapillary neoplasm is the most prevalent solid pancreatic tumor in children, while pancreatoblastoma is the most common malignant tumor. Insulinoma is the most common pediatric pancreatic tumor of the endocrine pancreas. Malignant tumors require a complete, often radical, surgical resection. However, pancreatic parenchyma-sparing surgical procedures are utilized for benign tumors and low-grade malignancy to preserve gland function. This review will discuss the epidemiology, pathophysiology, clinical and diagnostic characteristics, and management options associated with both common and rare solid pancreatic masses in children. We will also discuss current challenges encountered in their evaluation and treatment.

Contrast-Enhanced Ultrasound in Children: Implementation and Key Diagnostic Applications

Contrast-enhanced ultrasound (CEUS) utilization is expanding rapidly, particularly in children, in whom the modality offers important advantages of dynamic evaluation of the vasculature, portability, lack of ionizing radiation, and lack of need for sedation. Accumulating data establish an excellent safety profile of ultrasound contrast agents in children. Although only FDA-approved for IV use in children for characterizing focal liver lesions and for use during echocardiography, growing off-label applications are expanding the diagnostic potential of ultrasound. Focal liver lesion evaluation is the most common use of CEUS, and the American College of Radiology Pediatric LI-RADS Working Group recommends including CEUS for evaluation of a newly discovered focal liver lesion in many circumstances. Data also support the role of CEUS in hemodynamically stable children with blunt abdominal trauma, and CEUS is becoming a potential alternative to CT in this setting. Additional potential applications that require further study include evaluation of pathology in the lung, spleen, brain, pancreas, bowel, kidney, female pelvis, and scrotum. This review explores the implementation of CEUS in children, describing basic principles of ultrasound contrast agents and CEUS technique and summarizing current and potential IV diagnostic applications based on pediatric-specific supporting evidence.

Diagnostic challenge of a cystic solid pseudopapillary tumor in pancreas: A case report

A solid pseudopapillary tumor should be included in the differential diagnosis of every pancreatic cystic lesion. A constellation of microscopic morphology and immunohistochemistry, in addition to the clinical history, aids in reaching the correct diagnosis.

Differential diagnosis of pancreatoblastoma (PB) and solid pseudopapillary neoplasms (SPNs) in children by CT and MR imaging

OBJECTIVES

To determine whether features on computed tomographic and/or magnetic resonance imaging can differentiate pancreatoblastoma (PB) from solid pseudopapillary neoplasms (SPNs) of the pancreas in children.

METHODS

Clinical and imaging data for 20 cases of SPNs and 14 cases of PB confirmed by surgery or biopsy were retrospectively analysed. The size, border, calcification, haemorrhage, solid/cystic component proportion, intratumoural vessels, tumour capsulation, pancreatic duct dilatation, peripancreatic vessel invasion, distant metastasis status and apparent diffusion coefficient (ADC) values of the two groups were examined, and key diagnostic features were identified. Statistical analysis was performed using the chi-square test and Student's t test. Sensitivity and specificity values were calculated when a single criterion was used.

RESULTS

Age ≤ 5 years, elevated serum α-fetoprotein (AFP), larger size, ill-defined border, calcification, absence of haemorrhage, intratumoural vessel, peripancreatic vessel invasion and distant metastasis differentiated PB from SPN (p < 0.05). ADC values of SPN were higher than those of PB (p = 0.001). There were no significant differences regarding tumour capsule (p = 0.435), pancreatic duct dilatation (p = 1.000) or cystic degeneration area over 50% of the tumour volume (p = 1.000) between the two groups.

CONCLUSIONS

The following features are helpful for differentiating PB from SPN: age ≤ 5 years, elevated serum AFP, larger size, ill-defined border, calcification, haemorrhage absence, intratumoural vessel, peripancreatic vessel invasion, distant metastasis and lower ADC value.

KEY POINTS

• CT and MRI are helpful to differentiate pancreatoblastoma (PB) from solid pseudopapillary neoplasms (SPNs) of the pancreas in children. • The following features are helpful to differentiate PB from SPN: age ≤ 5 years, elevated serum AFP, larger size, ill-defined border, calcification, absence of haemorrhage, intratumoural vessel, peripancreatic vessel invasion, distant metastasis and lower ADC value.

Pediatric ultrasonography of the pancreas: normal and abnormal findings

The pancreas is easily investigated in children thanks to the relative lack of fat tissue and the large left hepatic lobe with an optimal acoustic window. The use of high frequency, even linear transducers, usually results in detailed images of all pancreatic areas. A wide spectrum of pancreatic pathologic conditions can be identified and monitored at ultrasound although they are relatively uncommon during childhood compared to the adult. In this paper we briefly review the anatomy, technique, and sonographic aspects of normal and pathological pediatric pancreas.

Solid pseudopapillary and malignant pancreatic tumors in childhood: A systematic review and evidence quality assessment

A systematic review of 32 studies reporting on 489 children with pancreatic tumors was performed. The most prevalent histologic subtype was solid pseudopapillary tumor (SPT) (61.3%). Pancreaticoduodenectomy was the most commonly performed operation (48%). Neoadjuvant chemo/radiotherapy was utilized in 3.9, 36.2, 25, and 27.8% of patients with SPTs, pancreatoblastomas (PBLs), neuroendocrine tumors, and exocrine carcinomas, respectively. Adjuvant chemotherapy (75.6%) and radiation (34%) were most commonly utilized in PBLs. All-cause mortality was highest in exocrine carcinomas (50%). Overall, 98.8% of patients with SPTs survived. PBL exhibited the highest recurrence rate (14.7%) within a mean of 23.5 months.

Solid pseudopapillary tumor of the pancreas: A difficult presentation of an uncommon tumor

We present a case of a solid pseudopapillary tumor of the pancreas incidentally discovered in a child who presented following sports-related abdominal trauma. This case is a unique presentation of an uncommon pancreatic tumor that posed a diagnostic dilemma to radiologists as it appeared as a hematoma by imaging and initial image-guided aspiration. Ultimately, MRI and core biopsy were needed to make the final diagnosis. This entity posed a problem during the differential diagnosis given the appearance and extenuating circumstances.

Imaging features of primary malignant pancreatic tumors in children

OBJECTIVE

The purpose of this article is to describe the sonographic, CT, and MRI features of primary malignant pancreatic tumors of childhood.

CONCLUSION

Most children with a pancreatic tumor present with a solid pseudopapillary tumor that is usually well marginated and has solid and cystic areas surrounded by a fibrous capsule. Pancreatoblastoma is more aggressive than solid pseudopapillary tumor. The imaging features are those of a large heterogeneous tumor. Ductal adenocarcinoma is rare in children and has a poor prognosis.