Diagnosis: Prostatic duct adenocarcinoma. 

Comment: This is a rare variant of adenocarcinoma comprising 0.4% to 0.8% of prostate cancers. Although can be the sole component, more frequently is associated with conventional acinar adenocarcinoma. These tumors show a variety of architectural patterns including papillary fronds and/or cribriform pattern.The epithelial lining is composed of pseudostrified tall columnar epithelium somewhat reminiscent of endometrial adenocarcinoma. The tumor is PSA positive immunoistochemically, however, has variable expression in the serum. A study by Christensen et al. showed a more aggressive behavior than acinar prostate cancer (Cancer 1991; 67: 2118-24). Prostatic duct adenocarcinomas were in an advanced pathologic stage by the time of presentation and had a much higher short-term failure rate after radical prostatectomy compared with acinar cancers.