Case report: cachexia of the kidney--a cause of pseudo-hydronephrosis

Various pitfalls in diagnosing early hydronephrosis on ultrasound (US) have been recognized. We present a case where the appearances on US mimicked bilateral hydronephrosis in a patient undergoing treatment for recurrent colonic carcinoma. Comparison with a previous ultrasound examination demonstrated marked loss of renal sinus fat. Doppler studies demonstrated normal venous flow within each portion of the "dilated collecting system". In oncology, renal cachexia should be remembered as one of the causes of pseudo-hydronephrosis.