Prostatic adenocarcinoma which closely mimics benign prostatic hyperplasia is adenocarcinoma with pseudohyperplastic pattern. The morphological similarities include large glands with papillary infoldings and branching. However the distinguishing features are crowded glands, nuclear enlargement, occasional to frequent nucleoli and abundant pink intraluminal secretions and crystals. There can be large glands with straight luminal borders. These tumors are not only difficult to diagnose but they are also difficult to grade as Gleason scoring system does not account for this histologic pattern. Some of these tumors have shown extraprostatic extension and it has been recommended that pseudohyperplastic adenocarcinoma should not be regarded as a low grade cancer. This is a case report of prostatic adenocarcinoma with pseudohyperplastic pattern and signet ring cells in the glandular epithelium mimicking colonic hyperplastic polyp. In addition there is an associated pattern of high grade foamy gland carcinoma and occasional signet ring cells in the stroma. This combination has not been described in previous studies.