Electron microscopy in the diagnosis of tumours

Abstract

This review deals with the value of electron microscopy in human tumour diagnosis. Electron microscopy continues to be useful, largely because of the limitations of immunohistochemistry, currently the most important ancillary diagnostic technique for problem tumours. Prompt fixation in buffered fixative, appropriate sampling, avoidance of freezing or drying and of the mis-interpretation of reactive or entrapped normal cells as neoplastic elements, are emphasized as important factors. The ability to detect good and poor structural preservation in toluidine-blue-stained resin sections is also pointed out. Applications in non-immunoreactive tumours, tumours with unexpected or confusing immunophenotype, and exceptionally unusual tumours, are given, all of which may benefit from electron microscopy. Despite limitations (sampling, and dependence of interpretation on good preservation) the technique continues to be useful by supplying a unique kind of information, namely, the way molecules are assembled into supramolecular structures (organelles), having specific functions and diagnostic significance.