Applicability of Paediatric Kerrison's Punch in Endoscopic Transcanal Mastoidectomy-Harnessing a Fresh Perspective.

BACKGROUND

A major challenge in the histopathological examination of scalp biopsies is to perform an adequate evaluation of all the hair follicles present in the tissue. Transverse sectioning is currently the preferred technique to demonstrate every follicular structure in a punch biopsy specimen, although diagnostic accuracy is dependent on subjective evaluation of follicular morphology and hair size.

OBJECTIVES

To determine if computer-based morphometry and three-dimensional (3D) image reconstruction software can be used to evaluate scalp biopsies from patients with non-cicatricial alopecias.

METHODS

Nine 4-mm scalp punches were taken from nine patients with noncicatricial alopecias and step-sectioned transversely at 0.1-mm intervals from the epidermal surface to the subcutaneous fat. Each tissue section was then digitized and analysed using morphometric and 3D image reconstruction software. Morphometric data and 3D images were collated with clinical and conventional light microscopic diagnoses, as well as follow-up information.

RESULTS

In four of the nine patients, results of morphometric analysis concurred with conventional clinicopathological diagnoses. In the remaining five patients, morphometry revealed a lower telogen count in one patient and higher telogen count in four patients. One of the four patients with a higher telogen count also had a low mean hair diameter and miniaturized anagen follicles in the 3D image that were suggestive of early androgenetic alopecia (AGA). 3D virtual microscopic imagery allowed the direct visualization of colour-coded, scaled hair follicles which demonstrated characteristic changes in alopecia areata, AGA and telogen effluvium.

CONCLUSIONS

Our study demonstrated the feasibility of using morphometric and 3D reconstruction software to evaluate scalp biopsies. With further validation, this technique may prove to be more sensitive to detect subtle quantitative and qualitative follicular changes in non-cicatricial alopecias.