Objective: To determine which patients with asymptomatic microscopic haematuria (AMH) should be investigated to exclude significant urological pathology.
Patients and methods: The study comprised a prospective audit of a standard protocol for investigating all patients referred with haematuria over one year in a haematuria clinic in the urology department serving Tayside, Scotland. Investigations included urine culture and cytology, flexible cystoscopy, and upper tract imaging which consisted of both excretory urography and renal ultrasonography in many of the patients.
Results: A total of 381 patients with microscopic haematuria was investigated. No malignancy was found in any < 50 years of age (n = 131); in patients aged > 50 years the overall incidence of malignancy was 7.5% (19/250). The asymptomatic patients in this group had a lower incidence (5%, 6/126) of malignancy than the symptomatic patients (10.5%, 13/124) but this difference did not reach statistical significance. There was no statistically significant difference in the incidence of urological malignancy between men and in women with microscopic haematuria. During the same period, 233 patients were referred with frank haematuria; in these patients, those aged < 50 years had a 10% incidence of malignancy (6/60), while in those aged > 50 years the incidence was 34.5% (60/173). A total of 18 patients (4.7%) with microscopic haematuria had upper tract calculi, comprising 5.3% (7/131) of patients aged < 50 years and 4.4% (11/250) of those > 50 years with microscopic haematuria.
Conclusions: The investigation of older patients with microscopic haematuria (and all those with frank haematuria) is well justified, as malignancy will be found in a significant proportion even if they are asymptomatic. The benefit of a full urological investigation of younger patients with microscopic haematuria is debatable.