Carcinoma and dysplastic lesions of the prostate. A histomorphological analysis of 50 total prostatectomies by step-section technique.

50 prostate carcinomas which were totally prostatectomized together with removal of the seminal vesicles in all cases and pelvic lymphadenectomy in 38 cases were studied histologically. The material was cut by step-section technique in 5 mm thick slices and "large area slides" were made. 4 of the 50 carcinomas were morphologically circumscribed (stage I), 6 tumors were limited to the organ (stage II) and 40 prostate carcinomas had already penetrated the capsule, i.e. fascia of Denonvillier (stage III). In 12 cases the seminal vesicles were involved, regional lymph node metastases were seen 8 times. The carcinomas were mainly localized in the peripheral part of the organ (28 X in the periphery, 21 X both peripherally and centrally and only 1 X in the centre). Multifocal tumor growth was found in 30 cases (60%). The main mass of tumor was mostly situated in the middle (25 X) and caudal (15 X) zone of the prostate. During the course of tumor growth the expansion was directed centrally but then mainly longitudinal and parallel to the urethra. By progressing tumor volume there was a noticeable increase in capsular penetration as well as infiltration of the seminal vesicles and lymph node metastases. Histologically 10 carcinomas showed a uniform pattern, a unique solid and/or cribriform tumor architecture was never observed. 90% of the pluriform carcinomas consisted of the morphological stage III.