Fragments of prostatic biopsy: characteristics, dimensions, and number.

Prostate needle biopsy can give important clinical information on tumor extension and grading, useful prognostic parameters for the therapeutic choice and prognostic definition. Currently about the 25% of positive biopsies for carcinoma contain only small foci of cancer that makes histopathological evaluation often the difficult and less reliable. We reviewed the literature about different methods to perform needle biopsies and methods to improve histologic yield of prostatic biopsies in order to obtain more histopathological information on the specimens to improve diagnostic accuracy on core biopsy. We report our initial experience using the preembedding methods proposed by Rogatsch. The best method to perform a prostate biopsy includes the use of using 18-gauges needles, single specimen identification and subsequent orientation of every bioptic fragment by inking its proximal end. We performed the preembedding technique of the fragments, proposed by Rogatsch et al., stretching the fragment between two nylon meshes enclosed in a tissue cassette in formalin. The full length of the biopsy is within the section plane. This technique partially modified in our preliminary experience with the employment of two sponges containing 10% buffered formalin placed in a tissue cassette (2.8 x 3.3 cm). This "sandwich" technique has furnished evident advantages for the pathologist, optimizing the visible area for section plane in comparison to that obtainable from free floating core biopsies. In conclusion, routinely application of the preembedding prostatic core biopsies could improve the accuracy of the histopathological examination and therefore provide more reliable data on tumor extension and grade.