Latent carcinoma of the prostate: the probability of identifying small lesions in routine histology.

In 3,072 open prostatectomy specimens covering a 25-year period 117 (4%) showed frank carcinoma. A further 74 cases showed areas of occult carcinoma or atypical hyperplasia. These focal lesions had an average diameter of 1 mm and 96% were situated in the peripheral regions of the specimen. In view of the situation of these lesions and their small size, an improved method of taking blocks for histological sections from prostatectomy specimens is proposed, resulting in an increased probability of demonstrating the areas of occult malignancy.