Colitis cystica profunda (CCP) is an uncommon benign condition characterized by mucin-filled cysts located in the submucosa, frequently associated with the solitary ulcer and rectal prolapse syndromes. The diagnosis of this entity is important as it can mimic rectal cancer and therefore may result in unnecessary surgical resection. Endoscopic examination and barium enema findings are suggestive but not specific, neither are superficial biopsy findings. Transrectal ultrasound is helpful in the diagnosis by imaging the layers of the rectal wall. The authors report a 16-year-old male with a rectal lesion mimicking malignant mass on endoscopic examination. The lesion was defined as CCP, based on MR imaging findings which disclosed multiple noninfiltrating submucosal cysts, confirmed by histopathological examination. To our knowledge, this is the first case of CCP in the radiology literature describing MRI findings.