Relative proportions of tissue components in the prostate: Are they related to the development of symptomatic BPH in Korean men?

Objectives. To investigate the high prevalence of lower urinary tract symptoms in Korean men with a small prostate, we studied the proportions of histologic components of prostatic adenoma in patients with symptomatic benign prostatic hyperplasia. Methods. Prostatic adenoma specimens were obtained from men with symptomatic benign prostatic hyperplasia who underwent open prostatectomy or transurethral resection of the prostate. Patients were divided into three groups according to the prostate volume as measured by preoperative transrectal ultrasonography (group 1, 20 to 40 cm(3), 21 men; group 2, 41 to 80 cm(3), 22 men; and group 3, greater than 80 cm(3), 23 men). The age distribution and the severity of symptoms were comparable in these three groups (P >0.05). The proportion of the stroma in the prostatic adenoma and the-proportions of smooth muscle, collagen types I, II, III, and V, fibronectin, and laminin in stromal tissue were determined using automatic image analyzer quantitatively. Results. The proportions of the stroma in the prostatic adenoma specimens of groups 1 and 2 were significantly greater than in group 3 (P <0.05). The proportions of smooth muscle, collagen types I, III, and V, fibronectin, and laminin were not significantly different in the three groups (P >0.05). The relative smooth muscle proportion in the prostatic adenoma (proportion of stroma x proportion of smooth muscle in stromal tissue) in groups 1 and 2 was significantly greater than in group 3 (P <0.05). Conclusions. These results suggest that the dynamic component of bladder outlet obstruction, which is mediated by smooth muscle tone, may play a more important role in the development of symptomatic benign prostatic hyperplasia in Korean men.