[Pathology of prostatic carcinoma: new approaches to its development and biological significance]

The common prostatic carcinoma consists of two different types with respect to development, spread, histopathology, morphogenesis and prognosis. These are the carcinoma of the dorso-peripheral zone and the tumor which is located in the antero-central zone. The first one corresponds to the clinically manifest prostatic carcinoma, the latter is identical to the prostatic carcinoma incidentally found by the pathologist examining unsuspicious prostatic tissue from transurethral resection or simple prostatectomy. The antero-central tumor growths to the ventral area and infiltrates the apex and bladder neck frequently. It is biologically not as important as the tumor of the dorso-peripheral zone showing a lower grade of malignancy in the majority of cases. In 2 of 3 cases, however, there are one or more coexisting carcinomas in other, frequently dorso-peripheral zones. Therefore the risk of the individual patient can not precisely be estimated. The carcinoma of the dorso-peripheral zone does predominate by frequency and biological potency. The incidence of positive lymph nodes strongly increases when seminal vesicle invasion is found. The disturbance of the epithelial-stromal interaction is the starting point of carcinogenesis. In the first step, PIN results of an intraductal proliferation of atypical epithelial cells, whereas atypical hyperplasia develops from an overwhelming proliferation of tubular glands with progressive decrease of basal cells. Based on the topographical and histological relationships the role of PIN as a precursor lesion of the dorso-peripheral prostatic carcinoma is considered, whereas atypical hyperplasia is thought to represent the preneoplastic state of the incidental and antero-central prostatic carcinoma, respectively.