Examination of the urinary sediment in dipstick haematuria

Introduction: About 5% of patients referred with dipstick-detected haematuria will have a bladder or renal carcinoma. It has been suggested that examination of the urinary sediment to confirm microscopic haematuria is helpful in the selection of patients for full urological investigation. We have used the data from a prospective evaluation of an out-patient haematuria clinic to explore this hypothesis. Patients and methods: A total of 474 patients referred with dipstick haematuria was assessed by history, examination, urine analysis, urine microscopy, flexible cystoscopy and IVU. Results: Thirty patients (6'3%) had TCC of the bladder and three (0.06%) had renal adenocarcinoma. The sensitivity and specificity of urine examination for the detection of these tumours are shown in the table. Sensitivity (%) Specificity (%) Positive dipstick urine analysis (> Trace) 64 51 Microscopic haematuria 29 97 (> 1 red blood cell/high-power field) Malignant cells on cytology 27 99 Coulter-counter analysis 18 98 (normal mean cospuscular volume) Conclusion: The results of this study indicate that the examination of urinary sediment for erythrocytes or malignant cells lacks the sensitivity necessary to exclude patients referred with dipstick haematuria from cystoscopy. Flexible cystoscopy may be the most useful initial investigation for these patients, with further testing dependent upon findings within the bladder.