Transrectal US in the diagnosis of localized colitis cystica profunda.

Colitis cystica profunda (CCP) mimicks rectal carcinoma, which makes distinguishing this benign lesion from the more common rectal neoplasm clinically and pathologically difficult. When transrectal ultrasound (US) was used in this case, three features of CCP were seen. There were multiple lesions, which did not penetrate beyond the submucosa. A large cystic component was seen, with a layer of uniform thickness in two of the three lesions. Non-solid contents and a lack of infiltration can be visualized at transrectal US, which helps diagnose CCP.