The dedifferentiation of metastatic prostate carcinoma.

Two hundred consecutive staging lymphadenectomies with metastatic prostate adenocarcinoma and 100 consecutive autopsies with widely disseminated metastatic prostate adenocarcinoma were identified. The metastases from 41% of the staging lymphadenectomies were entirely differentiated (gland forming) and an additional 43% were predominantly (50% or more) differentiated. In contrast, the metastases from 70% of the autopsies were entirely undifferentiated (non-gland forming) and an additional 18% were predominantly undifferentiated. Further, five patients with completely or predominantly differentiated metastases in staging lymphadenectomies were found to have widespread completely or predominantly undifferentiated metastases at autopsy 4-7 years later. These findings suggest that dedifferentiation occurs within metastases and that dedifferentiation within metastases may be important in understanding the widespread dissemination of metastatic prostate carcinoma.