Presentation
Work up for abdominal pain
Patient Data
An 18 mm cyst-like lesion is noted in the mid portion of the left kidney that contains three small marginal calcified foci and is accompanied by adjacent cortical thinning. On delayed post-contrast images, the lesion shows excreted contrast accumulation.
A 70×48×27 mm well-defined fat density intramuscular mass is noted at the right lateral aspect of the abdominal wall, consistent with lipoma.
Case Discussion
Features on CT images are consistent with a calyceal diverticulum, and regarding marginal calcification foci and adjacent cortical thinning, it seems to be secondary or acquired.
A calyceal diverticulum will appear similar to a renal cyst on early post-contrast CT images. Still, in the excretory phase, the cystic structure fills with contrast material due to communication with the collecting system, and the layering of contrast material is seen within. This helps differentiate the calyceal diverticulum from a renal cyst, which does not connect with the collecting system.