The pathologist's guide to fixatives.

Proper tissue fixation is essential to ensure the highest level of specimen evaluation. Pathologists and laboratory staff are frequently consulted by clinical counterparts regarding what fixative should be used for different tissues or to enable a diagnosis of a specific condition. It is vital for the patient that the pathologist provides accurate information to ensure proper fixation. Frequently, once a tissue has been fixed inadequately or inappropriately, remedial changes may no longer be possible. Most often formalin is an adequate choice, if not the optimal one; however, there are certain situations when placing the tissue in formalin may limit the ability to reach a definitive diagnosis. It is imperative for pathologists to have the knowledge to communicate which fixative is optimal. Furthermore, as we move into a world of personalized medicine, where ancillary testing has both diagnostic and specific therapeutic implications, knowledge about how different fixatives affect immunohistochemistry, cytogenetics, and molecular studies becomes even more significant. This chapter provides practical information regarding common fixatives, their mechanism of action and optimal uses.

Optimizing prostate specimen handling for diagnosis and prognosis.

Optimal processing, handling, and sampling of prostatic biopsies, transurethral resections, and radical prostatectomy specimens ensure accurate diagnosis and staging. Prognostic factors derived from careful examination of tissue samples are critical for patient management, including cancer volume, extraprostatic extension, surgical margins, vascular/lymphatic invasion, and perineural invasion. This chapter addresses these important issues, including recent recommendations of a consensus panel of the International Society of Urologic Pathologists.