Fig. 1(A) A well-defined, partly enhancing 4.0 cm-sized mass is present in the pancreatic head of case 1 (arrows). (B) An endoscopic ultrasound image shows a 4.0 cm-sized, round, well-defined and heterogeneously hypoechoic solid mass in the pancreatic head. (C) A whitish-tan, solid mass with hemorrhage is noted in the pancreatic head on the resected specimen (arrows).
Fig. 2(A) In case 1, there are inconspicuous nucleoli (arrowhead) and nuclear grooves (arrow). (B) In case 2, the tumor cells show a rosette formation with a myxoid globule in the background of hemorrhage. (C) Case 3 is characterized by the papillary arrangement composed of delicate fibrovascular core with attached multilayer monotonous cuboidal cells. (D) In case 3, both a cluster of tumor cells and scattered ones are identically showing relatively uniform, monotonous features.
Fig. 3(A) Some areas of tumor show a solid sheet with thin fibrovascular cores and clear or eosinophilic granular cytoplasm. Intraluminal myxoid globules (B) and eosinophilic hyalinized stroma
(C) are frequently observed.
Fig. 4In case 3, the tumor cells show an immunopositivity for vimentin (A), progesterone receptor (B), and β-catenin (C) and an immunoreactivity for a loss of E-cadherin (D).
Table 1Summary of immunohistochemical findings
Table 2EUS-FNA cytologic features in 43 cases of SPN described in the English literature
Table 3Immunohistochemical findings described in the English literature