PMC7314643_01
Ultrasound demonstration of the tumor. (A) Contrast-enhanced ultrasound image with size measurement as 5.0 cm at 19 s post contrast administration. (B) The relationship of the stomach and the tumor. Intact five layers of the stomach wall between the stomach and the tumor were indicated as: 1 M - superficial mucosal layer (hyperechoic), 2 MM - muscularis mucosal layer (hypoechoic), 3 SM - submucosal layer (hyperechoic), 4 PM - muscularis proper layer (hypoechoic), and 5 S - serosa (hyperechoic).
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Notably, gastric tissue adjacent to the tumor showed an intact structure of five layers of the stomach wall (Figure 1).
Preoperative CT investigation with (A) non-enhanced, (B) arterial phase, (C) venous phase, and (D) delayed phase images.
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On the contrary, a contrasted computed tomography (CT) was unable to rule out that the tumor was originated from the stomach wall due to tight tumor-stomach adjacency (Figure 2).
Preoperative MR investigation with (A) T1 weighted, (B) T2 weighted, (C) arterial phase images, and (D) diffusion-weighted imaging.
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Further magnetic resonance imaging (MRI) suggested that the tumor was close to the stomach wall with gastric mucosa uninvolved (Figure 3).
Results of pathology analysis. (A) An overview of histology by H&E stain. Zone A indicates the area composed of abundant spindle cells. Zone B indicates the area with loose structure and paranuclear vacuolization. Zone C indicates spindles cells with nuclear arrangement of the palisades. (B) Immunohistochemistry analyses showing expression of CD117, DOG-1, S100, Ki67, SMA, CKpan, p53, and CD34. (C) Pathological analysis of the relationship between the gastric wall layers and the GIST tumor.
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Immunohistochemistry results also supported the characteristic marker expression as gastric stromal tumor, including positive CD117, positive DOG-1, negative S100, 5% positive Ki67, negative SMA, negative CKpan, 8% positive p53, and positive CD34 (Figure 4).