Hematuria in patients with malrotated kidneys.

Persistent microscopic hematuria and proteinuria were found in 3 patients with malrotation of the kidneys. Preliminary investigations did not disclose the etiology. Renal histology showed different pathologies, including focal segmental hyalinosis and sclerosis, minor glomerular abnormality and lupus nephritis. The previous belief of strangulation of the malrotated kidney leading to hematuria is not confirmed. Hematuria is due to coincidental glomerulonephritis. Phase-contrast microscopic examination of midstream urine sediment constantly revealed dysmorphic red blood cells suggestive of renal origin. This technique definitely adds important clinical information and helps to determine the initial investigations in these patients with congenital anomalies of the kidney complicated by persistent hematuria.