SEM in service pathology: a review of its potential role.

New medical technology evolves through distinct phases. Initial technical proving is followed by a phase of detailed data recording, often with no detailed attempt to fill any specific service requirements. Next an attempt is made to establish correlations with other techniques and results, with a view to defining any unique attributes of the technology in particular fields. Detailed service-related applications are then worked out, but the final adoption of new instrumentation into clinical practice depends not only on the success of its technical performance, but also on its cost-effectiveness. This paper reviews studies of clinically-derived material from the viewpoint of a U.K. diagnostic pathologist. Detailed comparisons are drawn between the evolution of SEM on the one hand and of LM and CTEM on the other. An attempt is made to identify areas of practice in which SEM might make the greatest impact in the foreseeable future. It is proposed that paraffin-embedded tissue in pathology back files may provide a valuable source of investigative material for diagnostic SEM.