PMC5422749_01
a Abdominal ultrasound shows a well-defined hypoechoic mass measuring 30 mm in diameter with internal heterogeneity in the pancreatic tail. b Abdominal contrast-enhanced CT (early phase) shows a well-defined mass lesion measuring approximately 30 mm in diameter, extending from the gastric wall to the pancreatic tail. c, d Abdominal MRI shows a mass lesion with low signal intensity on T1-weighted imaging (c) and slightly high signal intensity on T2-weighted imaging (d).
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F1
Abdominal ultrasound showed a well-defined hypoechoic mass measuring 30 mm in diameter with internal heterogeneity in the pancreatic tail (Fig. 1a). Abdominal contrast-enhanced computed tomography (CT) showed a mass lesion measuring approximately 30 mm in diameter, extending from the gastric wall to the pancreatic tail (Fig. 1b). Abdominal magnetic resonance imaging (MRI) showed a mass of hypointensity on T1-weighted imaging and slight hyperintensity on T2-weighted imaging (Fig. 1c, d).
a FDG-PET shows slight accumulation of FDG at the site of the lesion. No other significant accumulation is seen. b Conventional endoscopy shows a smooth bulge in the posterior wall of the middle gastric body. Endoscopic ultrasound shows a hypoechoic mass measuring 30 mm in diameter located between the pancreatic tail and the stomach. The internal echo is heterogeneous and suspected to be partially continuous with the fourth layer of the stomach (arrow).
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F2
Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed slight accumulation of FDG at the site of the lesion (Fig. 2a). Conventional endoscopy showed a smooth bulge in the posterior wall of the middle gastric body, suggesting an extragastric compression (Fig. 2b).
a, b Histopathological findings show cord-like proliferation of spindle-shaped cells with minimal atypia, and the intercellular spaces are filled with thick bundles of collagen fibers. a HE stain, x100. b HE stain, x400. Immunostaining shows that the cells are negative for c-kit (c) and positive for nuclear beta-catenin (d). c c-kit, x400. d beta-catenin, x400.
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F3
The cells were positive for vimentin and negative for c-kit (Fig. 3). In histopathological findings (Fig. 3), the lesion showed cord-like proliferation of spindle-shaped cells with minimal atypia, and thick bundles of collagen fibers filled the intercellular spaces.