Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare, low-grade malignant tumor accounting for approximately 1%–3% of all pancreatic neoplasms (1–3). It predominantly affects young females (4) and generally carries a favorable prognosis after complete surgical resection (5).

Tumor rupture in SPN is uncommon, and reports involving children with SPN are exceedingly rare. Rupture is clinically significant because it may increase the risk of peritoneal dissemination and subsequent tumor recurrence (6, 7). Although several case reports and small case series have described ruptured SPN, data specific to the pediatric population remain scarce, particularly concerning long-term oncologic outcomes (8). Due to the rarity of this condition, evidence guiding optimal management and postoperative surveillance in children is limited. In particular, recurrence risk, histopathologic correlations, and surgical outcomes have not been comprehensively evaluated in pediatric cases of ruptured SPN.

This study presents a 20-year, single-center experience with children diagnosed with ruptured SPN, focusing on clinicopathologic features, operative management, and long-term outcomes. We further describe recurrence patterns and potential prognostic factors to inform surgical decision-making and refine surveillance strategies for this rare pediatric entity.

To our knowledge, this study represents the largest case series to date focusing exclusively on children with ruptured SPN—an exceedingly rare clinical entity. With a median follow-up of 47 months, we conducted a comprehensive assessment encompassing clinical presentation, operative findings, histopathologic characteristics, and long-term outcomes. Suspected recurrence arose in five patients, whereas confirmed recurrence was identified in only two (28.6%). Among the cases with peritoneal seeding, two were attributable to tumor rupture at presentation, whereas the remaining events represented later disease progression. Both confirmed cases involved large tumors exceeding 10 cm and exhibited peripancreatic soft tissue extension, whereas other histologic variables—such as capsule integrity, lymphovascular invasion, and lymph node involvement—were not consistently associated with relapse. Notably, our clear distinction between suspected and confirmed recurrence offers a novel perspective and underscores the importance of cautious interpretation of postoperative surveillance imaging.

Although SPN generally carries an excellent prognosis, recurrence or metastasis may occur in a small subset of patients (11). Pooled analyses of long-term data from non-ruptured SPN cohorts have reported recurrence rates between 10% and 15% (12, 13). A comprehensive meta-analysis identified several adverse prognostic factors, including tumor diameter greater than 5 cm, lymphovascular or nodal invasion, synchronous metastasis, and positive resection margins. Subsequent studies further proposed that tumors exceeding 8 cm, the presence of microscopic malignant features, synchronous metastases, and an elevated Ki-67 index (>4%) were predictive of recurrence (14). More recently, a large retrospective Chinese series involving 195 patients found incomplete tumor encapsulation to be an independent predictor of “malignant SPN” behavior, although the overall 10-year disease-free survival after R0 resection remained favorable at approximately 94% (15). Consistent with these observations, multiple systematic reviews and contemporary cohort studies have emphasized that, despite its classification as a low-grade neoplasm, a subset of SPNs display distinctly aggressive biological behavior (16, 17). Our study differs from these prior investigations by focusing specifically on pediatric cases of ruptured SPN and by explicitly differentiating between radiologic suspicion and pathologically confirmed recurrence. Unlike earlier reports that often relied solely on imaging or clinical impression, our findings demonstrate that not all radiologic abnormalities represent confirmed recurrence. This distinction carries substantial clinical importance when determining surveillance intensity and the need for surgical re-exploration.

Our findings, in conjunction with previous reports, provide several clinically meaningful insights. Rigorous long-term surveillance remains essential in the management of ruptured SPN. Although pathologically confirmed recurrence occurred in only a small subset of patients, radiologic suspicion arose in the majority (five of seven), highlighting the need for careful longitudinal assessment that integrates clinical evaluation, imaging interpretation, and—when indicated—surgical exploration. A risk-adapted surveillance approach may therefore be warranted. In our cohort, the two confirmed recurrence cases shared tumors >10 cm with peripancreatic soft tissue extension, although the small sample size precludes any statistical inference. Additional prognostic variables identified in broader SPN literature—including tumor size greater than 5–8 cm, positive resection margins, lymphovascular invasion, nodal metastasis, microscopic malignant features, and elevated Ki-67 index—should also inform the intensity and duration of postoperative follow-up in both ruptured and non-ruptured SPN cases (18). In our cohort, Ki-67 was not available because it is not routinely performed for SPN in children at our institution.

Meticulous surgical management is likewise critical in rupture cases. Comprehensive intraoperative exploration of the peritoneal cavity, extensive lavage, and confirmation of negative resection margins may help reduce the risk of peritoneal dissemination. In this context, the choice between laparoscopic and open surgery also warrants consideration. Minimally invasive resection was selectively attempted in patients with smaller, well-circumscribed tumors without extensive preoperative evidence of rupture, whereas open surgery was favored when rupture was strongly suspected, tumor size was large, or adhesions or adjacent organ involvement were anticipated. Importantly, peritoneal seeding was observed in both open and laparoscopic procedures, and rates of suspected or confirmed recurrence were comparable between approaches. No case of iatrogenic rupture or tumor spillage occurred during minimally invasive surgery, supporting its feasibility in carefully selected pediatric patients.

Although two patients presented with synchronous metastases involving the omentum, liver, or para-aortic lymph nodes, all metastatic deposits retained classic SPN morphology without high-grade atypia, increased mitotic activity, or extensive necrosis. Therefore, none fulfilled the WHO 2022 histologic criteria for solid pseudopapillary carcinoma. Confirmed recurrence later developed in two patients, both showing regional or peritoneal dissemination rather than new distant organ metastasis. This observation suggests that even histologically benign-appearing SPNs possess the potential for locoregional relapse, reinforcing the importance of meticulous intraoperative inspection of the entire peritoneal cavity and vigilant postoperative surveillance, including careful assessment of the pelvic cavity. Postoperative pancreatic function was well preserved in all patients, with no cases of endocrine or exocrine insufficiency and normal HbA1c values in the two patients assessed. These findings reinforce that long-term functional outcomes are excellent in pediatric SPN, even in ruptured cases. Notably, hepatic recurrence was among the confirmed relapse sites in our cohort. Because small or subcapsular hepatic lesions may be difficult to detect on CT, particularly in young patients, supplemental MRI should be considered when CT findings are inconclusive or when clinical or biochemical suspicion persists. Implementation of a structured surveillance protocol alternating CT and MRI examinations may enhance postoperative monitoring sensitivity and facilitate earlier detection of subtle or atypical recurrences.

This study has several limitations that warrant consideration. First, the small sample size (N = 7) inevitably limits statistical power and precludes robust multivariate analysis. Second, its retrospective, single-center nature may introduce referral bias, while variations in imaging surveillance protocols could have influenced recurrence detection rates. Third, histopathologic data were derived from archival pathology reports rather than standardized re-review of all specimens, potentially introducing reporting heterogeneity. Fourth, one patient was lost to follow-up before possible reoperation, resulting in uncertainty regarding recurrence status.

To strengthen and validate these findings, multicenter collaboration and registry-based studies are needed, particularly in children, in whom ruptured SPN remains rare. Prospective protocols that standardize imaging intervals, surgical decision-making, and criteria for intervention based on risk stratification will be essential for refining postoperative surveillance strategies. In addition, future research integrating molecular and immunohistochemical profiling—including CTNNB1 mutation status, Ki-67 proliferation index, and hormonal receptor expression—may help elucidate the biological mechanisms underlying recurrence and enable more precise, individualized risk prediction in children with ruptured SPN.

These observations support a risk-adapted surveillance strategy, with prolonged and meticulous imaging follow-up particularly in patients with large tumors or peripancreatic extension.

In summary, although suspected recurrence was common among children with ruptured SPN, pathologically confirmed recurrence occurred in only a small subset. In our cohort, both confirmed recurrence cases involved tumors larger than 10 cm with peripancreatic soft tissue extension, although these observations are descriptive and limited by the small sample size. These findings highlight the importance of cautious interpretation of postoperative imaging, the value of risk-adapted long-term surveillance, and the necessity of histopathologic confirmation to distinguish true recurrence from radiologic abnormalities. Larger, multicenter studies are needed to better define recurrence risk and guide evidence-based management strategies for this rare clinical entity.