1Department of Radiology, Tsukuba Memorial Hospital, 2Department of Surgery, Tsukuba Memorial Hospital, 3Institute of Clinical Medicine, University of Tsukuba
mucinous adenocarcinoma of the colon, pseudokidney sign, ultrasonography
The patient was a 74-year-old woman complaining of pain in the lower right abdomen. Ultrasonography showed a hypoechoic mass with an echogenic core in front of the right kidney, suggestive of pseudokidney sign, a term originally used for bowel tumors, intussusception, and some inflammatory conditions. Most of these entities involve thickening of the bowel wall and appear as a hypoechoic rim. In our case, several strand echoes spread out from the echogenic core to the hypoechoic rim. The CT and pathological findings showed the hypoechoic rim to correspond to collection of mucin, the echogenic core, and to nodular tumors and feces. The spreading strand echoes could represent connective tissue within the subserosal space or adjacent to the outer bowel wall.