[Cytological diagnosis of the prostate].

The historical development is described for the technique of transrectal aspiration biopsy of the prostate [23, 25] and for the cytological diagnosis of prostatic cancer [6, 12, 19]. The cytological criteria for the diagnosis of prostatic cancer and its different malignancy grades, its regression after therapy, other malignancies of the prostate and the various forms of prostatitis are described in detail. The validity of the histological and cytological diagnosis of the prostate are compared. The accuracy of the histological and the cytological diagnosis of prostatic carcinoma is judged as being equal for both procedures with about 3% false positives and about 7% false negatives each. Both procedures allow a prognostically valid and reproducible grading of malignancy of prostatic cancer. For evaluation of tumor regression after therapy the histological investigation of a punch biopsy is preferred. By cytological investigation a histogenetic classification of most prostatic tumors is possible. It is also possible to differentiate cytologically the various forms of prostatitis. Except for rare, exceptional cases, the cytological diagnosis of prostatic lesions is equivalent to the histological diagnosis, but requiring a skilled cytologist. Aspiration biopsy of the prostate is less risky and less uncomfortable for the patient than the punch biopsy.