Solid pseudopapillary tumors of the pancreas: Specific pathological features predict the likelihood of postoperative recurrence.

BACKGROUND: Since their introduction in the WHO classification, the incidence of solid pseudopapillary tumors (SPTs) of the pancreas has progressively increased, mainly because of the widespread use of cross-sectional imaging. Few recent studies have analyzed the biological behavior of SPTs, but reliable data on long-term follow-up are needed. METHODS: Retrospective analysis of two Institutions with high caseload, The Department of General Surgery-Pancreas Institute, University of Verona Hospital Trust and the Department of General Surgery, Massachusetts General Hospital, Harvard Medical School, was carried out. Data from 131 consecutive resections for SPT performed during the last three decades were collected and analyzed. RESULTS: The majority of patients were female (86.3%) with a median age of 33 (7-68) years. The prevalent location was the pancreatic tail (33.5%). Applying the WHO criteria, 16 (12.2%) SPTs were considered malignant due to the presence of at least pancreatic parenchyma (9.9%), perineural (4.6%), and/or angiovascular invasion (2.3%). After a median of 62 months after surgery, only two patients had a recurrence (1.5%). Both of them fulfilled the WHO criteria for malignant SPT (vs. 10.7% of those who did not recur, P = 0.01), had an infiltrative growth pattern (vs. 10.8%, P = 0.01), pancreatic parenchyma invasion (vs. 9.7%, P = 0.01) and capsular invasion (vs. 4.9%, P = 0.004). CONCLUSION: Overall, SPTs are associated with excellent survival results after surgical resection. Disease recurrence is extremely rare, and might occur if the primary tumor presents with either pancreatic parenchyma or capsule invasion. J. Surg. Oncol. 2016;114:597-601. © 2016 Wiley Periodicals, Inc.

Growth pattern of serous cystic neoplasms of the pancreas: observational study with long-term magnetic resonance surveillance and recommendations for treatment.

BACKGROUND AND AIMS: The natural history and growth pattern of pancreatic serous cystic neoplasms (SCNs) are not well understood. This study was designed in order to get insight into the growth rate of SCNs and to suggest recommendations for their management. METHODS: Patients with well-documented incidentally discovered or minimally symptomatic SCNs who underwent yearly surveillance MRI were analysed using a linear mixed model. The growth rate and the effects of different fixed factors (sex, personal history of other non-pancreatic malignancies, radiological pattern, clinical presentation, tumour site) and random factors (age and tumour diameter at the time of diagnosis) on tumour growth were investigated. RESULTS: Study population consisted of 145 patients. Estimated overall mean growth rate was 0.28 cm/year, but the growth curve analysis showed a different trend between the first 7 years after the baseline evaluation (growth rate of 0.1 cm/year) and the subsequent period (years 7 to 10, growth rate of 0.6 cm/year, p<0.0001). Tests for fixed effects demonstrated that an oligocystic/macrocystic pattern and a personal history of other tumours are significant predictors of a more rapid mean tumour growth (p<0.0001 and 0.022, growth rates of 0.34 cm/year). Furthermore, tumour growth significantly increased with age (p = 0.0001). CONCLUSION: Overall, SCNs grow slowly, and an initial non-operative approach is feasible in all the asymptomatic or minimally symptomatic patients. The oligocystic/macrocystic variant, a history of other non-pancreatic malignancies and patients' age impact on tumour growth. In any case, a significant growth is unlikely to occur before 7 years from the baseline evaluation. Tumour size at the time of diagnosis should not be used for decisional purposes.