Dermatopathology – the link between ancillary techniques and clinical lesions

Background: Histopathology has been essential in advancing our knowledge in veterinary dermatology. However, morphological features and histological patterns cannot always reveal an aetiological diagnosis. Objectives: Several ancillary techniques can assist in achieving an aetiological diagnosis. Some of these techniques have found their way into routine diagnostic dermatopathology, whereas others are still mainly used in research. This review discusses the utility, strengths, advantages/disadvantages and challenges associated with each technique. Methods: Digital microscopy, immunohistochemistry, immunofluorescence, salt-split skin, Western blots, electron microscopy, PCR, in situ hybridization, tissue microarrays, next-generation sequencing, DNA microarrays and laser microdissection are discussed. Conclusions: It is crucial to understand the limitations of each technique and to correlate the results both with pathological findings and the clinical presentation. As such, dermatopathology will remain the important link between benchtop science, available results from ancillary techniques and clinical veterinary dermatology.