Prediction of Recurrence of Completely Resected Pancreatic Solid Pseudopapillary Neoplasms in Pediatric Patients: A Single Center Analysis

Background: Many previous studies have investigated the risk factors for the recurrence of pancreatic solid pseudopapillary neoplasms (SPNs), although a consensus has not yet been reached, despite this effort. We aimed to identify the predictive factors for recurrence in patients with SPNs who underwent complete surgical resection of the tumor. Methods: We retrospectively analyzed the records of pediatric patients with SPNs who underwent surgical resection at a single center between 2001 and 2018. Results: During the study period, 47 patients with SPNs underwent radical resection of the tumor. The median age of the patients was 14 (8–18) years. R0 resection was confirmed in every case and none of the patients presented with systemic metastasis at the time of diagnosis. The median follow-up period was 53.1 (30.8–150.8) months. Of the 47 patients, only two (4.2%) experienced recurrence. Using comparative analysis, we found that some factors such as a large tumor size, peripancreatic tissue invasion, and capsule invasion did not increase the risk of recurrence of SPNs. Lymph node metastasis was the only significant factor for recurrence in our study (p = 0.043). Conclusion: During our single center analysis, we found that only lymph node metastasis was a predictive factor for recurrence of SPNs among patients who underwent complete tumor resection. Long-term follow-up is required to determine whether SPNs will recur if lymph node metastasis is observed after surgery. Furthermore, therapeutic benefits of routine lymphadenectomy or sentinel lymph node biopsy should be investigated in future studies to reduce the risk of recurrence in patients with SPNs.

SOLID PSEUDOPAPILLARY NEOPLASM OF THE PANCREAS: PRESENTATION OF A CASE AND REVIEW OF THE LITERATURE

Solid pseudopapillary neoplasms (SPN) of the pancreas are rare tumors, occurring in 1-2% of all pancreatic neoplasms; of these 10 to 15% have an aggressive presentation. Most of the patients present disease localized to the pancreas, however, between 9-15% may present local invasion and metastasis. The clinical presentation in the vast majority of SPN is asymptomatic, even despite a large tumor size. We present a case of a 16-year-old female patient with a psedupapillary tumor of the pancreas (Frantz tumor) who was admitted due to abdominal pain and weight loss lasting 3 months.

MRI-based radiomics approach for differentiation of hypovascular non-functional pancreatic neuroendocrine tumors and solid pseudopapillary neoplasms of the pancreas

Background This study aims to investigate the value of radiomics parameters derived from contrast enhanced (CE) MRI in differentiation of hypovascular non-functional pancreatic neuroendocrine tumors (hypo-NF-pNETs) and solid pseudopapillary neoplasms of the pancreas (SPNs). Methods Fifty-seven SPN patients and twenty-two hypo-NF-pNET patients were enrolled. Radiomics features were extracted from T1WI, arterial, portal and delayed phase of MR images. The enrolled patients were divided into training cohort and validation cohort with the 7:3 ratio. We built four radiomics signatures for the four phases respectively and ROC analysis were used to select the best phase to discriminate SPNs from hypo-NF-pNETs. The chosen radiomics signature and clinical independent risk factors were integrated to construct a clinic-radiomics nomogram. Results SPNs occurred in younger age groups than hypo-NF-pNETs (P < 0.0001) and showed a clear preponderance in females (P = 0.0185). Age was a significant independent factor for the differentiation of SPNs and hypo-NF-pNETs revealed by logistic regression analysis. With AUC values above 0.900 in both training and validation cohort (0.978 [95% CI, 0.942–1.000] in the training set, 0.907 [95% CI, 0.765–1.000] in the validation set), the radiomics signature of the arterial phase was picked to build a clinic-radiomics nomogram. The nomogram, composed by age and radiomics signature of the arterial phase, showed sufficient performance for discriminating SPNs and hypo-NF-pNETs with AUC values of 0.965 (95% CI, 0.923–1.000) and 0.920 (95% CI, 0.796–1.000) in the training and validation cohorts, respectively. Delong Test did not demonstrate statistical significance between the AUC of the clinic-radiomics nomogram and radiomics signature of arterial phase. Conclusion CE-MRI-based radiomics approach demonstrated great potential in the differentiation of hypo-NF-pNETs and SPNs.