Introduction: The objective of this study was to evaluate the accuracy of using intravesical prostatic protrusion (IPP) as a parameter for the diagnosis of prostate adenoma (PA), as well as to determine the relationship between the site of PA and bladder outlet obstruction. IPP was determined with the use of transabdominal ultrasonography (TAUS).
Methods: A total of 77 consecutive adult men aged 30-85 years with haematuria or undergoing checkup for bladder tumour were enrolled. International Prostate Symptom Score (IPSS), and the results of uroflowmetry, TAUS and cystourethroscopy were assessed. All cases of IPP were classified into grades 0 (no IPP), 1 (1-5 mm), 2 (6-10 mm) or 3 (> 10 mm). PA diagnosis was confirmed using flexible cystourethroscopy. The sites of PA were classified as U0 (no adenoma), U1 (lateral lobes), U2 (middle lobe) or U3 (lateral and middle lobes).
Results: Of the 77 patients, 11 (14.3%) had no IPP. PA was confirmed using cystourethroscopy for all patients with IPP and for 7 of the 11 patients without IPP. Of the 37 patients with prostate volume < 20 g, 29 (78.4%) had IPP. Sensitivity, specificity, as well as positive and negative predictive values for diagnosing PA using only IPP were 90.4%, 100.0%, 100.0% and 36.4%, respectively. Higher sensitivity (95.9%) and negative predictive value (50.0%) were obtained when PA was used together with peak urinary flow rate (Qmax) < 20.0 mL/s. The mean Qmax of patients classified as U1 (n = 39) was 16.0 mL/s, while the mean Qmax in those classified as U2 (n = 12) and U3 (n = 22) was 11.9 mL/s and 8.9 mL/s, respectively.
Conclusion: All patients with IPP had PA, and PA in the middle lobe was more obstructive than those in lateral lobes. Patients without IPP may still have PA.