There are a few types of prostate cancer and the condition is often present in different parts of the prostate. The precursor to prostate cancer is known as prostatic intraepithelial neoplasia, and is also found in different locations within the prostate.
Prostatic adenocarcinoma: This type of tumor is the most frequent form of prostate cancer and accounts for 90 to 95% of prostate cancer. Prostatic adenocarcinoma is occurring in the cells lining the glandular organ of the prostate, the area responsible for the secretion of the chemicals that make up a large portion of seminal fluid. The most common site of origin of prostate cancer is the peripheral zone where two thirds of the prostate glandular tissue is located. Typically, prostatic adenocarcinoma is a slow growing form of cancer, and when found early there is a good chance of achieving cures.
Small cell carcinoma: This type of cancer is made of small round cells. It is a very aggressive form of prostate cancer that does not lead to a change in prostate specific antigen (PSA). It thus can be more difficult to detect than adenocarcinoma. It is usually detected, when it has already advanced.
Squamous cell carcinoma: This type of prostate cancer is non glandular and like small cell carcinoma does not lead to an increase in prostate specific antigens (PSA). Squamous cell carcinoma is a very aggressive form of cancer.
Prostatic sarcomas: This type of cancer is extremely rare and accounts for less than 0.1% of primary prostate cancer. Prostatic sarcoma occurs in relatively younger men between the ages of 35 and 60. The tumor is made up of prostate cancer cell types that are capable of developing into connective tissues, lymphatic vessels, and blood vessels originating from smooth muscles of the prostate.
Twenty-five percent of cases present with metastatic disease at the time of diagnosis. Prostatic sarcoma remains localized for a viable period of time before it spreads locally to the bladder, rectum or perineum. Over more time the tumor will spread to distant locations like the lungs, brain, bones or liver. The most common sites of distant metastasis are the lungs.
Transitional cell carcinomas: This type of cancer rarely develops in the prostate but derives from primary tumors present in the bladder or urethra.