PMC6365397_01
(a) Abdominal computed tomography (CT) reveals a 25-mm-diameter round encapsulated mass with peripheral calcification in the body of pancreas (red arrow heads). The solid part shows gradual slight enhancement. The pancreas distal to the tumor is markedly atrophic (blue arrow heads). The dilatation of main pancreatic duct (MPD) is not observed. (b) Endoscopic ultrasonography (EUS) shows a 23-mm mass with several cystic components in the pancreas body (red arrow heads). (c) Histopathological images of samples from endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) shows a highly cellular mass with papillary clusters of small and uniform cells with oval nuclei surrounding a fibrovascular core (hematoxylin and eosin stain; original maginification, x200).
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The pancreas distal to the tumor was markedly atrophic (Fig. 1a). EUS showed a 23-mm heterogenous mass with several small cystic components (Fig. 1b). The tumor was found to be a highly cellular mass with papillary clusters of small and uniform cells with oval nuclei surrounding a fibrovascular core, confirming the preoperative diagnosis of SPN (Fig. 1c).
(a) Intraoperative frozen section of the distal pancreas margin shows no evidence of acinar cells, which indicates the exocrine dysfunction, although scattered foci of islets of Langerhans are observed (blue arrows), corresponding to end-stage chronic pancreatitis. (b) Central pancreatectomy without reconstruction of the distal pancreas was performed.
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Moreover, there was no evidence of acinar cells in the distal atrophic pancreas, which indicated the exocrine dysfunction, although scattered foci of islets of Langerhans were observed (Fig. 2a). As a result, we chose to perform central pancreatectomy and close pancreas distal stump with the automatic suturing device instead of pancreaticojejunostomy or pancreaticogastrostomy (Fig. 2b).
Macroscopic examination of the resected specimen (a-c). The tumor is encapsulated, comprising central hemorrhage, necrosis (b), and solid portions (c). Main pancreatic duct (MPD) seems to be compressed from the cranial side to the caudal (a red arrow) (c).
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The cut section revealed the solid area and the zone of hemorrhagic necrosis (Fig. 3a-c). MPD seemed to be compressed from cranial side to caudal (Fig. 3b).
Histological examination of the surgical specimen reveals that the tumor cells have monotonous small, oval nuclei, and form the pseudo-papillary structure in a hemorrhagic background (a). The tumor compresses and partly involves the main pancreatic duct (MPD) from cranial side to caudal (a blue arrow) (b). In the distal atrophic parenchyma, the vestige of dilated MPD is observed (blue arrow heads) (c).
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Histologically, the tumor cells have relatively small and monotonous oval nuclei, and form the pseudo-papillary structure in a hemorrhagic background (Fig. 4a). The tumor compressed the MPD from cranial side to caudal, and partly involved MPD (Fig. 4b). In the distal atrophic parenchyma, the vestige of dilated MPD was observed (Fig. 4c).
On immunohistochemical examination, the tumor cells are weakly positive for synaptophysin (a), chromogranin A (b), and alpha1-antitrypsin (c), and positive for alpha1-antichymotrypsin (d), nuclear beta-catenin (e), and CD10 (f).
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CD10 (Fig. 5d-e). Consistent with the diagnosis based on EUS-FNA biopsy, we diagnosed the patient with SPN of the pancreas.