Many of these carcinomas are small and clinically insignificant. However, some are not, and prostatic adenocarcinoma is second only to lung carcinoma as a cause for tumor-related deaths among males. None of these methods can reliably detect all prostate cancers, particularly the small cancers. Transrectal needle biopsy, often guided by ultrasound, is useful to confirm the diagnosis, although incidental carcinomas can be found in transurethral resections for nodular hyperplasia. Cytologic features of adenocarcinoma include enlarged round, hyperchromatic nuclei that have a single prominent nucleolus.
Mitotic figures suggest carcinoma.
Less differentiated carcinomas have fused glands called cribriform glands, as well as solid nests or sheets of tumor cells, and many tumors have two or more of these patterns. Prostatic adenocarcinomas almost always arise in the posterior outer zone of the prostate and are often multifocal. Prostatic adenocarcinomas are usually graded according to the Gleason grading system based on the pattern of growth. Adenocarcinomas of the prostate are given two grade based on the most common and second most common architectural patterns. These two grades are added to get a final grade of 2 to 10.