Urinary sediment in storage diseases: differential diagnosis of Nieman-Pick disease by cytologic means

Renal involvement in lipid storage diseases is well recognized. Electron microscopy or chemical analysis of urinary sediment has been used for the diagnosis of these diseases. Urine cytology, supplemented by cytochemistry, polarization, and autofluorescence, helped us in the diagnosis of Niemann-Pick disease in an infant. The unique findings are described, and the differential diagnosis of storage cells by cytochemical stains is discussed.