Large cloisons.

Large masses of normal glomerular (cortical) tissue situated deeply within the kidney and properly called cloisons, can often be mistaken for tumors. The radiographic characteristics of 20 cases are described, including location at or above the middle one-third of the kidney (93%) and bilaterality (60%). Three unusual, but associated papillary-calicine features include the "teat and udder" sign, which derives from the relation of the cloison and its small papillae which resemble a cow's udder and teats, calicine stem displacement, and absence of calicine cup stretching. Further investigation of the cloison by nephrotomography or technetium-labeled glucoheptonate may be necessary in doubtful cases to confirm this benign condition.