RESUMO
Hematuria indicates the presence of an abnormal amount of red blood cells [RBCs] in the urine. The causes of hematuria are multiple and its investigation is crucial. One of the methods for differentiating between nephronal and non-nephronal hematuria is estimation of the percentage of dysmorphic RBCs in the urine. In this cross-sectional prospective study, the data showed that the presence of 25% dysmorphic RBCs in the urine were diagnostic with a sensitivity of 92.5% and a specificity of 83.3%. Furthermore, the utility of diagnostic values of dysmorphic RBCs under light microscopy were compared with those under standard phase contrast microscopy. Results showed that there was no significant difference in the diagnostic accuracy between these two methods. In conclusion, a single, clinically relevant threshold percentage [25%] is now defined with acceptable sensitivity and specificity. Moreover, the results showed no significant difference in the diagnostic efficacy of light microscopy versus phase contrast in the diagnosis of dysmorphic hematuria