Functional property, norepinephrine content and morphometric findings in human hyperplastic prostate

Can histopathology predict treatment outcome following high-energy transurethral microwave thermotherapy of the prostate? Results of a biopsy study

BACKGROUND

Despite good results of high-energy transurethral microwave thermotherapy (TUMT) in the treatment of benign prostatic hyperplasia, it is still difficult to predict the response to treatment on an individual basis. Besides clinical baseline parameters, intrinsic histological parameters are suggested to play a role in the response variance after TUMT. In this study we analyzed histological parameters (vessel density and epithelium-stroma (E/S) ratio) in patients who were selected for high-energy TUMT and related these parameters to clinical outcome.

METHODS

We treated 42 patients with high-energy TUMT, who prior to treatment agreed upon ultrasonographic investigation of the prostate in combination with biopsies of the peripheral and transitional zones of the prostate. For all separate biopsy locations, the histological stained prostate slides were morphometrically quantified with computer assistance and analyzed for E/S ratio and vessel density. Response to treatment was measured by using standardized response evaluation criteria and was correlated with histological outcome.

RESULTS

The E/S ratio in the inner gland biopsies tended to be higher in the good response group compared to the very poor responders. Furthermore, a clear trend was seen towards a lower vessel density in good responders. Large prostates and prostates with a high E/S ratio responded well to the high-energy thermotherapy.

CONCLUSIONS

Histopathological parameters of the prostate tend to be moderately predictive for clinical response in this research population. Poor responders appeared to have a somewhat higher vessel density in all prostate biopsy sides, and there was also a trend towards a lower E/S ratio in these patients.

Relation between urethral elasticity and bladder outlet obstruction and histologic composition of the prostate in patients with benign prostatic hyperplasia

OBJECTIVES

In benign prostatic hyperplasia (BPH), bladder outlet obstruction is caused by mechanical blockage resulting from an enlarged prostate, and by the increased tone of prostatic smooth muscle. In patients with obstructive BPH, the prostatic urethra urodynamically corresponds to the flow-controlling zone (FCZ). We sought to investigate the relation between the obstruction and elastic properties of the FCZ and the histologic composition of the prostate in symptomatic patients with BPH.

METHODS

The grade of infravesical obstruction was classified according to preoperative pressure-flow data from 30 men with symptomatic BPH, and the elastic properties of the FCZ were evaluated as the mean elastance, which was calculated using the three-parameter model. The area densities of smooth muscle, fibrous tissue, epithelium, and lumen were determined by quantitative morphometry, using BPH tissue obtained by transurethral resection.

RESULTS

The area density of smooth muscle had a negative correlation with mean elastance (p = -0.50, P <0.01), the linear passive urethral resistance relation (p = -0.43, P <0.05), and the group-specific urethral resistance factor (p = -0.39, P <0.05). No other histologic element was correlated with these variables.

CONCLUSIONS

Our results suggest that urethral elasticity and bladder outlet obstruction grade are influenced by the relative content of smooth muscle within the prostate in patients with BPH.