Abstract

Primary signet ring cell carcinoma of the prostate is extremely rare and about 18 cases have been reported in the literature. We report two cases of primary signet ring cell carcinoma of the prostate, arising in 79-year-old and 65-year-old men. Both cases were the poorly differentiated adenocarcinoma of the prostate with many signet ring cells. Signet ring cells were positive for prostatic specific antigen and prostatic acid phosphatase but negative for neutral and acid mucins. In summary, the signet ring cell carcinoma of the prostate is a rare variant of poorly differentiated adenocarcinoma of the prostate. The orgin of the prostate should be considered in cases of metastatic signet ring cell carcinoma, particularly when the signet ring cells are negative for neutral and acid mucins. Prostatic specific antigen and prostatic acid phosphatase should also be performed to confirm the primary signet ring cell carcinoma of the prostate.

• Keywords: Prostate;Signet ring cell carcinoma;PSA;PAP