Endoscopic ultrasound-guided fine-needle aspiration for diagnosis of solid pseudopapillary tumors of the pancreas: a multicenter experience

Background and study aims: Solid pseudopapillary tumors of the pancreas are rare, low-grade, epithelial neoplasms that are usually discovered incidentally in young women. Distinguishing solid pseudopapillary tumors from other pancreatic tumors, especially pancreatic endocrine tumors, can be challenging. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in this context remains unclear. The purpose of this study was to describe the endoscopic ultrasound features of solid pseudopapillary tumors and the role of EUS-FNA in the preoperative diagnosis of these tumors.

Patients and methods: Patients from five tertiary referral centers with surgically confirmed solid pseudopapillary tumors who had undergone preoperative EUS-FNA were included. The endoscopic ultrasound findings, cytologic descriptions, immunostaining results, operative records, surgical pathology, and results of the most recent clinical follow-up were reviewed.

Results: A total of 28 patients were identified (four men [14 %], 24 women [86 %], mean age ± standard deviation [SD] 35 ± 10 years). Solid pseudopapillary tumors had been found as incidental findings on cross-sectional imaging in 50 % of cases. The mean tumor size ± SD was 42 ± 19.5 mm and the majority were located in the pancreatic body and tail. The endoscopic ultrasound report described a well-defined, echo-poor mass in 86 %; the tumors were solid in 14 patients (50 %), mixed solid and cystic in 11 patients (39 %), and cystic in three patients (11 %). A preoperative diagnosis of solid pseudopapillary tumor was made in 21 patients (75 %) on the basis of EUS-FNA cytology. Surgical resection was performed in all cases. Laparoscopic resection was performed in eight of these patients (29 %).

Conclusions: A solid pseudopapillary tumor should be included in the differential diagnosis of any well-demarcated, echo-poor, solid or mixed solid/cystic pancreatic lesion seen during endoscopic ultrasound, particularly in young women. The diagnostic accuracy of EUS-FNA for solid pseudopapillary tumors was 75 % in this study. A definitive preoperative diagnosis can guide the surgical approach in selected cases.

References

• 1 Frantz V K. Tumors of the pancreas. In: Anonymous atlas of tumor pathology, Section 7, Fascicles 27 and 28. Washington DC, USA; Armed Forces Institute of Pathology 1959: 32-33
• 2 Kloppel G, Luttges J, Klimstra D S. Solid pseudopapillary neoplasm. In: Hamilton SR, Aaltonene LA, (eds.). World Health Organization classification of tumors: pathology and genetics of tumors of the digestive system. Lyon, France; IARC Press 2000 436: 473-480
• 3 Adamthwaite J A, Verbeke C S, Stringer M D. et al . Solid pseudopapillary tumor of the pancreas: diverse presentation, outcome and histology.  JOP. 2006;  7 635-642
• 4 Papavramidis T, Papavramidis S. Solid pseudopapillary tumors of the pancreas: review of 718 patients reported in English literature.  J Am Coll Surg. 2005;  200 965-972
• 5 Ky A, Shilyansky J, Gerstle J. et al . Experience with papillary and solid epithelial neoplasms of the pancreas in children.  J Pediatr Surg. 1998;  33 42-44
• 6 Bardales R, Centeno B, Mallery S. et al . Endoscopic ultrasound-guided fine-needle aspiration cytology diagnosis of solid pseudopapillary tumor of the pancreas: a rare neoplasm of elusive origin but characteristic cytomorphologic features.  Am J Clin Path. 2004;  121 654-662
• 7 Master S, Savides T. Diagnosis of solid pseudopapillary neoplasm of the pancreas by EUS-guided FNA.  Gastrointest Endosc. 2003;  57 965-969
• 8 Nadler E, Novikov A, Landzberg B. et al . The use of endoscopic ultrasound in the diagnosis of solid pseudopapillary tumor of the pancreas in children.  J Pediatr Surg. 2002;  37 1370-1373
• 9 Santini D, Poli F, Lega S. Solid papillary tumors of the pancreas: histopathology.  JOP. 2006;  7 131-136
• 10 Akiyama H, Ono K, Takano M. Solid pseudopapillary tumor of the pancreatic head causing marked distal atrophy.  Int J Pancreat. 2002;  32 47-52
• 11 Tipton S G, Smyrk T C, Sarr M G, Thompson G B. Malignant potential of solid pseudopapillary neoplasm of the pancreas.  Brit J Surg. 2006;  93 733-737
• 12 Zinner M J, Shurbaji M S, Cameron J L. Solid and papillary epithelial neoplasm of the pancreas.  Surgery. 1990;  108 475-480
• 13 Sclafani L, Reuter V, Coit D, Brennan M. The malignant nature of papillary and cystic neoplasm of the pancreas.  Cancer. 1991;  68 153-158
• 14 Fried P, Cooper J, Balthazar E. et al . A role for radiotherapy in the treatment of solid and papillary neoplasms of the pancreas.  Cancer. 1985;  56 2783-2785
• 15 Notohara K, Hamazaki S, Tsukayama C. et al . Solid pseudopapillary tumor of the pancreas, immunohistochemical localization of neuroendocrine markers and CD10.  Am J Surg Pathol. 2000;  24 1361-1371
• 16 Abraham S C, Klimstra D S, Wilentz R E. et al . Solid pseudopapillary tumors of the pancreas are genetically distinct from pancreatic ductal adenocarcinomas and always harbor beta-catenin mutations.  Am J Pathol. 2002;  160 1361-1369
• 17 Stommer P, Kraus J, Stolte M, Giedl J. Solid and cystic pancreatic tumors: clinical, histochemical, and electron microscopic features in ten cases.  Cancer. 1991;  67 1635-1641
• 18 Pettinato G, Manivel J C, Ravetto C. et al . Papillary cystic tumor of the pancreas: a clinicopathologic study of 20 cases with cytologic, immunohistochemical, ultrastructural, and flow cytometric observations, and a review of the literature.  Am J Clin Pathol. 1992;  98 478-488
• 19 Tanaka Y, Kato K, Notohara K. et al . Frequent beta-catenin mutation and cytoplasmic/nuclear accumulation in pancreatic solid pseudopapillary neoplasm.  Cancer Res. 2001;  61 8401-8404
• 20 Min Kim S, Sun C D, Park K C. et al . Accumulation of beta-catenin protein, mutations in exon-3 of the beta-catenin gene and loss of heterozygosity of 5q22 in solid pseudopapillary tumor of the pancreas.  J Surg Oncol. 2006;  94 418-425
• 21 Carricaburu E, Enezian G, Bonnard A. et al . Laparoscopic distal pancreatectomy for Frantz’s tumor in a child.  Surg Endosc. 2003;  17 2028-2031