A Histopathologic Study of Alopecia Using Transverse Sections

Kim, Myeon Soo; Chun, Duk Kyu; Lee, Yong Suk; Seo, Seung Lee; Kim, Bang Soon

Abstract

BACKGROUND: Conventional vertical sections of scalp biopsy specimens are often inadequate for the diagnosis of alopecia. Alternatively, a better approach can often be provided with the use of transverse sections continues, which is readily available and continues to grow in popularity.
OBJECTIVE
The purpose of this study was to compare the histopathologic findings of transverse and vertical sections of scalp biopsy specimens in various types of alopecia.
METHODS
A total of 27 scalp biopsy specimens obtained during the past 16 months for the evaluation of alopecia was processed for either transverse or vertical section, or for both. With these sections a quantitative morphologic study was done by counting a variety of follicular structures, and any specific histopathologic changes were recorded.
RESULTS
Diagnostic features that were better seen in vertical sections included quantitative morphologic changes of a variety of follicular structures such as total number of follicles, catagen and telogen hairs, vellus hairs and follicular stele, as were anagen-telogen ratios and terminal-vellus ratios. Other histopathologic findings that were better demonstrated in transverse sections included peribulbar inflammatory infiltrate for alopecia areata, miniaturization for androgenetic alopecia, trichomalacia and pigment cast for trichotillomania, and fat atrophy for pressure alopecia. In some cases, especially for scarring alopecia, vertical sections also allowed for useful adjunctive diagnostic information such as follicular destruction, dermal fibrosis and sclerosis, and interface change.
CONCLUSION
Transverse sections of scalp biopsy specimens provided many useful information in histopathologic diagnosis of alopecia. But, in some cases of scarring alopecia, vertical sections provided more diagnostic findings. To overcome the diagnostic limitation of transverse sections, therefore, observing both transverse and vertical sections at a time could be an alternative way of enhancing diagnostic yield of alopecia.