Fig. 1 Endorectal ultrasound a, Gray scale ultrasound showed a cystic mass in the submucosa, with clear boundary, poor internal transmission, and continuous echogenicity in the mucosal layer (yellow arrow). b, Color Doppler ultrasound showed a small amount of blood flow signal around the cystic mass, no obvious blood flow signal inside, and continuous echogenicity in the serous layer of the intestinal wall (yellow arrow).
Contrast-enhanced computed tomography (CECT): A round-like low-density lesion with a size of 3.1x2.4x2.2cm was observed in the submucosa of the anterior wall of the middle rectum, with calcification on the edge and no obvious enhancement. The rectal mucosa was smooth, the rectal wall was intact, the surrounding fatty space was clear, and no enlarged lymph nodes were seen (Figure 2).