CPD article: Histopathology: how to maximise sample submission

Histopathology is the study of alterations in tissue caused by disease, including inflammatory, infectious and neoplastic processes. It encompasses examination at a microscopic level, by a trained veterinary pathologist, of tissues (including biopsies and post-mortem samples) that have been retrieved by a veterinary practitioner. These tissues must be fixed in formalin, processed and stained before examination. Histopathology can be a key tool for practitioners, providing a diagnosis or assisting with treatment (Stidworthy and Priestnall, 2011).

In some cases, inadequate sampling, submission or iatrogenically induced artefacts can invalidate microscopic interpretation. An incomplete or incorrect clinical history can also lead to incorrect dissection or microscopic interpretation of the specimen. Furthermore, there will always be a small number of cases with non-specific or equivocal findings, even with excellent quality samples and thorough accompanying history, and it can be helpful to warn owners of this possibility before proceeding.

The following recommendations are general outlines and it is always recommended that the specific laboratory is contacted to discuss their sample submission requirements.