Acute gastrointestinal bleeding as the presenting manifestation of prostate Cancer

Gastrointestinal bleeding was the presenting manifestation in four patients without readily apparent prostate cancer. Three of these patients had laboratory evidence of acute disseminated intravascular coagulation (DIC) and one patient had a friable rectal mass. The diagnosis of prostate cancer was made in three patients by employing an immunoperoxidase technique for prostatic acid phosphatase in metastatic foci. Dramatic resolution of DIC occurred in two patients following hormone therapy. Radiation therapy was effective in controlling bleeding in another patient. Two patients are alive with no further bleeding episodes at 8 and 18 months follow‐up, respectively. In patients who present with a bleeding diathesis and adenocarcinoma of unknown primary, it is important to consider prostate cancer because of its frequent and prolonged responsiveness to hormonal therapy.