The significance of septations in a renal cyst.

Little is known about the significance of one or more septations within a renal cyst. The records of 26 patients whose sonographic and/or CT studies showed evidence of internal septations were reviewed to assess their significance. Thirteen patients underwent surgical exploration; in 10, the final diagnoses were benign lesions, while in three there were elements of renal cell carcinoma. Criteria are suggested to distinguish benign from malignant lesions. One or more thin septations alone is probably of no clinical significance, but if there are solid elements demonstrated, further evaluation is mandatory.