Figure 1

Computed tomography images. (A) Non-contrast CT scan revealed an irregular, hypodense mass (arrows) on the right colon; (B) In the arterial phase, the mass showed inhomogeneous hyper-enhancement (arrows); (C) In the late phase, the tumor showed persistent hyper-enhancement (arrows)."

Figure 2

Gray-mode ultrasound and contrast-enhanced ultrasonography images. (A) Gray-mode ultrasound showed an elliptical hypoechoic lesion occupying the hepatic flexure of colon; (B) The tumor showed homogeneous hyperenhancement in arterial phase (arrows); (C) The tumor was not obviously washed out in the late phase (arrows)."

Figure 3

Colonoscopy and histopathological microscopy images. (A) Colonoscopy revealed a cauliflower-like mass (arrows) in the transverse colon; (B) A histological section of biopsy tissue guided by colonoscopy viewed at low power (hematoxylin-eosin, original magnification ×10) showed that the mass was composed of normal mucous membrane and necrotic tissue (arrows)."

Figure 4

Histopathological microscopy images of the specimen after right hemicolectomy. (A) The histological section viewed at low power (hematoxylin-eosin, original magnification ×40) showed that the mucous membrane and muscularis mucosae were normal (green arrows), the submucosa and muscularis propria were invaded by cancer cells (red arrows); (B) The histological section viewed at high power (hematoxylin-eosin, original magnification ×100) showed that the tumor was composed of clear cells arranged in small nests divided by a regular network of small thin-walled blood vessels (arrows)."