Multiple Diagnostic Imaging of a Patient with Solid Pseudopapillary Tumour of the Pancreas: EUS, CT and FDG PET/CT

Solid pseudopapillary neoplam of the pancreas (SPNP) is a rare tumour, making up approximately 1 % to 3 % of pancreatic tumours. About 90 % of SPNPs occur in young women (mean age 35 years). SPNP rarely causes symptoms and is usually detected incidentally. Differentiating SPNP from other pancreatic tumours is very important, because surgical resection may provide favourable outcomes. Metastases or invasion to other organs has been reported in 15% to 20% of patients with SPNP. Histologically, the uniform, bland-appearing, epithelial cells of SPNP are similar to the cells making up other pancreatic endocrine neoplasms. However, SPNP cannot be regarded as a pure pancreatic endocrine neoplasm because of the absence of chromogranin A expression and low expression of other endocrine markers. SPNP has not been associated with specific serum tumour markers. CT and MRI are used for the diagnosis and staging of SPNP. On contrast-enhanced CT, SPNP shows isoattenuation on precontrast CT, weak enhancement during the arterial phase and gradually increased enhancement during the portal venous phase. SPNP can appear as an encapsulated lesion with cystic degeneration, necrosis, haemorrhage or calcification. MRI can characterise internal signal intensities, including a blood component, which is helpful in making a differential diagnosis. Dong et al. analysed CT and MRI findings from eight patients with SPNP and reported that four lesions showed mixed solid and cystic components, and the others appeared almost completely solid. Stoita et al. reported that EUS-guided fine-needle aspiration was a minimally invasive, safe and reliable diagnostic method for SPNP. They reported that all seven lesions examined were hypoechoic, heterogeneous and well circumscribed. Their findings are very similar to the findings in our patient. In addition, it is clear from the EUS images of our patient that EUS provides better images for evaluating SPNP lesions than US of the pancreas (Figs. 1e and f and 2). F-18 FDG PET/CT imaging findings of SPNP are rarely reported. Dong et al. reported varying SUVmax values ranging from 2.5 to 29.1 in eight patients with SPNP. They reported that tumours with high cellularity were associated with increased SUVmax. In our report, we described a patient with SPNP who was evaluated using multiple diagnostic imaging modalities, including PET/CT, CT, ultrasonography and endoscopic ultrasonography