Prostate
carcinomas begin as well-differentiated lesions. Before
metastases occur these
carcinomas dedifferentiate into moderately or poorly differentiated lesions and increase in size to at least 1 cm3. Well-differentiated lesions rarely metastasize and
metastases are rarely well differentiated. Positive staging
lymphadenectomies usually contain moderately differentiated
metastases. Patients with moderately differentiated
metastases have a statistically significant better survival than patients with poorly differentiated
metastases.
Metastases typically disseminate as they dedifferentiate, with stage D1
metastases being moderately differentiated and stage D2
metastases being poorly differentiated. "Prostate-specific" immunohistochemical techniques and serum
prostate-specific antigen levels may be helpful in determining whether a particular
metastases is from the prostate. However,
metastases of uncertain origin should rarely, if ever, be attributed to the prostate without confirmation that the patient has a prostate
carcinoma with histologic features capable of metastasizing.