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.