Diagnosis: Colonic adenocarcinoma secondarily invading the prostate.

Comment:  There was a history of a previous colectomy due to adenocarcinoma. There are some findings suspicious that this adenocarcinoma is not primary from the prostate: normal PSA, lymphatic invasion and nuclear atypias not consistent with prostate carcinoma. The normal PSA is also inconsistent for a very huge prostate. Actually the prostate was of normal size. There was a pelvic mass interpreted as prostate that corresponded to the recurrent colonic tumor involving secondarily the prostate. Immunohistochemistry was negative for PSA, PAP and CK7. It was positive for CK20, CDX2 and vilin.