Transverse sectioning in the evaluation of skin biopsy specimens from alopecic dogs by Professor Ross Bond and colleagues at the RVC
This study showed that transverse sectioning confers significant benefits and complements traditional vertical sectioning in the histological assessment of canine hair follicle diseases.
Skin biopsy specimens were taken from skin lesions in 31 alopecic dogs clinically suspected of having a range of atrophic, dysplastic and inflammatory diseases of hair follicles and/or adnexal glands. Fixed samples were bisected vertically and one half was embedded in the traditional vertical orientation, whilst the other half was sectioned transversely. Sections were reviewed independently and the kappa statistic was used to assess the agreement between histological findings from both section types.
Substantial overlap was seen in the main pathological features for the paired sections, but in many cases one or other of the two sectioning planes yielded superior visualisation of key features. For example, transverse sectioning enhanced assessment of the hair growth phase, follicular structure and architecture, and focal luminal or mural folliculitides, while vertical sectioning demonstrated diagnostically important epidermal pathology and dermal thinning.
This relatively simple modification of sample processing can provide further diagnostic information with no additional risk for the patient, so has a relevant application in a large number of dogs.