PROSTATE CAPSULE - COMPUTERIZED MORPHOMETRIC ANALYSIS OF ITS COMPONENTS

Objectives. There is little objective information on what is designate d as being the prostate capsule, We have quantified objectively with c omputerized image analysis the percentage of smooth muscle fibers (SMF s) surrounding the surgical specimens of radical prostatectomies. Meth ods. Ten radical prostatectomy specimens were used. Six different part s from each prostate lobe were analyzed. Thirty different fields were examined from each tissue section. for tissue sections, different stai ns were used: hematoxylin and eosin, Masson's trichrome, and immunohis tochemical staining with antiactin for the SMFs. Results. The mean thi ckness of the prostate capsule was 0.5 to 2 mm. The mean percentages o f SMFs in the different regions of the prostate capsule was 30.6%. No difference was noted between the percentage of SMFs in the prostatic c apsule compared with that in the prostate parenchyma itself (30.7%). C onclusions. This study provides objective evidence to demonstrate that the prostate does not have a true capsule. This capsule represents a fibromuscular band that probably should be considered as the extension of the internal parenchyma.