Methods for diagnosing prostate cancer, and differentiate prostate cancer from other prostate complications, and use of said method, and diagnosing and monitoring lymph gland metastasis, post operative examinations, and examinations during or after radiation, cytostatic, and androgen treatments are disclosed. The methods comprise injecting tracer-labelled PSA or hK2 specific antibodies, visualising PSA or hK2 producing tissue with the aid of a visualization method, and diagnosing prostate cancer from the difference in visualization.