Introduction

The prostate gland continues to generate clinical attention in view of the fact that it is commonly involved in benign and malignant neoplasms as well as infections.

The prostate gland is wedged between the bladder neck superiorly and the urogenital diaphragm inferiorly with the prostatic urethra passing through it. Anteriorly it is related to the pubic symphysis and posteriorly to the rectum.

This intimate relationship becomes very important when the organ is diseased leading to backpressure changes in the prostatic urethra, bladder, ureters and kidneys. Some of these pathological changes are detectable on ultrasonography. Certain findings on ultrasonography may however be incidental¹

We set out to evaluate the ultrasound findings in patients presenting with prostatic diseases.

Ultrasound is a non invasive, radiation free, cheap and readily available investigation modality¹ though the findings are operator dependent and its application and interpretation requires some level of training.

Objective

To evaluate the frequency of urological abnormalities in urinary tract ultrasonography in patients with prostatic diseases.

Methods

All patients presenting at the urodiagnostics specialist imaging centre, Makurdi, Benue state, Nigeria with clinical diagnosis of BPH, Ca prostate or prostatitis from May 2010 – April  2011 were evaluated sonologically with a portable mindray 1100 ultrasound machine fitted with  3 – 5MHz  multifrequency curvilinear transabdominal transducer and the findings were tabulated and analyzed using the SPSS software.

Results

A total of 126 patients were involved in the study with an age range of 47 – 80yrs with a mean of 65yrs.

Seventy seven (61.1%) patients had clinical diagnosis of BPH while 48 (38.1%) and 1 patient (0.8%) had diagnosis of cancer of the prostate and chronic prostatitis respectively. Fig 1 shows that BPH is the most prevalent diagnosis in the middle age group (45- 65years) while cancer of the prostate is the most prevent diagnosis in the elderly.

Figure 1

Diagnosis Vs age of patients

The prostate volume ranged from 27mls to 777mls with a mean volume of 99.2mls.

73 patients (96%) with BPH had regular capsular outline while 4 had irregular capsular outline

37 (77%) of patients with cancer of the prostate had irregular capsular outline while eleven patients the capsular outline appeared regular (Fig II).

Irregularity of the capsular outline is therefore more common in cancer of the prostate compared to BPH.

Figure 2

Capsular outline in different prostatic diseases

 About half (54%) of the patients with a diagnosis of cancer had nodules on ultrasonography out of which 65% were hypoechoeic while 35% were hyperechoeic. Multiple nodules were noted in 3 (11%) of patients. All multiple nodules were hypoechoeic in nature.

The patient with chronic prostatitis had an irregular capsular outline.

The bladder wall thickness ranged from 4 – 12mm with a mean of 7.76mm.

No bladder mass suggestive of tumour was noted in the studied patient population.

Four patients (3.2%) had bladder diverticula which were noted in the bladder neck.

Solitary urinary bladder calculus was noted in Nine (7.1%) of the patients while one patient (0.8%) had multiple stones.

Submucosal halo was noted in two (1.6%) of patients.

A kidney stone was noted in one patient (0.8%) while 4 patients (3.2%) had renal cysts. No solid renal masses noted in any of the patients studied.

Hydronephrosis was noted in 4 patients with BPH while seven patients with cancer of the prostate had hydronephrosis making up a total of 8.7% of patients with Hydronephrosis. (Table I)

Table 1

prevalence of hydronephrosis in studied patient population

Discussion

The general objectives for transabdominal ultrasonography in patients with prostatic disease are to establish baseline for subsequent management and also to detect abnormalities in the urinary bladder, ureters and kdneys that may influence management of the patients’ conditions.

This study revealed that the mean age of the patients in this Study is 65 years. This finding supports previous works 2, 3.

 In this study 65% of patients with cancer had hypoechoeic nodules corroborating the series by Yeboah2 in which 71% of cancers were hypoechoic, however 35% of the nodules in this series are hyperechoic as opposed to the 1% in his study. No isoechoeic nodules were noted in this study. 

Prostatic Carcimoma arise in 80% of cases in the peripheral zone. They are primarily hypoechoic but with increasing tumour size echogenicity becomes varied due to tumour infiltration 4

However, a transrectal transducer defines the zonal anatomy and hence has a better sensitivity and specificity than a transabdominal transducer which was used in our study. 

The incidence of bladder stone in our series is 6.3% this is comparable to 5% in Al-Durazis5 series but Rafique1 had found stones in 13.6% of patients in his series of 250 patients.

The incidence of bladder diverticulum is 3.2% however Quirinia A et al6 however had an incidence of 51% on cystography & 30% on urography. This is a subject for further study as our series only comprise of ultrasonic studies.

Bladder wall thickness has been noted to correlate with the extent of bladder outlet obstruction from prostatism in a series by Franco G et al7. An area of future study could be to correlate the bladder wall thickness on ultrasound with International Prostate Symptom Score of patients.

The incidence of kidney stones is 0.8% (1) correlating with one stone in a series of 128 patients with prostatism by Gerald de Lacey et al8 while Al-Durazi H m et al5 in Bahrain found 9 cases of renal stones in a series of 100 patients. The changes in incidence of stones may be related to weather condition which is a known factor in the development of urolithiasis.

The incidence of renal cyst in our study is 3.2% compared with 9% in Al-Durazi’s5 series while in the Gerald de Lacey8 series, they had 21%5, Koch et al had an incidence of 11.7% in a series of 556 patients with BPH9.

 Bilateral hydronephrosis was present in 8.7% of our studied patient population but Rafique had noted hydronephrosis in 3% of patients in his series1.

Conclusion

Transabdominal ultrasound assessment is imperative in patients with prostatic disease. This is not only because of the effects of the prostatic disease on the upper and the lower tracts but also of the fact that some of these patients may habour clinical conditions that may influence the management of the patients’ conditions.