Utility of horizontal and vertical sections of scalp biopsies in various forms of primary alopecias

Diffuse Lichen Planopilaris Masquerading as Diffuse Alopecia Areata

Introduction

Lichen planopilaris (LPP) is a primary lymphocytic cicatricial alopecia that represents a form of follicular lichen planus.

Case Presentation

We describe a case of coexisting diffuse LPP and female pattern hair loss masquerading as diffuse alopecia areata in a 32-year-old female.

Discussion

In complex cases such as this, dermoscopy-guided vertical and horizontal biopsies from androgen sensitive and insensitive areas are helpful in increasing diagnostic yield. Prompt initiation of treatment is key to halting disease progression. Long-term follow-up is important as resolution of clinical signs does not always correlate with the absence of disease progression.

The modified HoVert (mHoVert) method improves diagnostic certainty compared to the St John's protocol for alopecia biopsy specimens: A retrospective single center study

BACKGROUND

Access to vertical and transverse sections of a punch biopsy specimen improves the diagnosis of alopecia. Both two biopsy specimen and single-punch biopsy specimen techniques to visualize both transverse and vertical sections have been described. Their comparative diagnostic certainty is not known. We aimed to assess the diagnostic certainty of a modified HoVert (mHoVert) method, without direct immunofluorescence (DIF), compared to the St John's protocol, a two-biopsy technique with DIF.

METHODS

Fifty-seven cases of alopecia processed using the St John's protocol and 60 cases of alopecia processed using mHoVert were reviewed. Diagnoses made were rated as certain/probable, possible, or uncertain, depending on the language in the histopathology report. Cases processed by the St John's protocol had final diagnosis and DIF result recorded.

RESULTS

In the mHoVert group, significantly more diagnoses were certain/probable (66%, 95% confidence interval [CI]: 57%-75%), compared to 46% (95% CI: 36%-56%) of diagnoses in the St John's protocol group (p = 0.005). DIF result did not affect the final diagnosis in any of the 57 cases reviewed.

CONCLUSIONS

DIF is not required in the diagnosis of most cases of alopecia. The mHoVert method provides more certain/probable diagnoses than the St John's protocol and can reduce cost and patient morbidity.

The role of the scalp biopsy in the evaluation of alopecia

A biopsy should be performed whenever the diagnosis is in doubt. A 4-mm punch biopsy sectioned horizontally at multiple levels is best. In general, noncicatricial alopecia should be sampled where hair is sparsest (most involved area), and cicatricial alopecia should be biopsied in an area of active disease, which is best determined using a dermatoscope and is most often at the margin of a lesion. The goal with cicatricial alopecia is to capture both follicular scars as well as actively inflamed hairs. Information provided by the clinician to the pathologist can be decisive in rendering a definitive diagnosis. The wording of the biopsy report provides a clue to the confidence of the pathologist's diagnosis.

Horizontal Histopathology Correlation with In Vivo Reflectance Confocal Microscopy in Inflammatory Skin Diseases: A Review

Horizontal histopathological sections (HHSs) have been reported to show a strong correlation with images obtained via in vivo reflectance confocal microscopy (RCM), as both reflect the same horizontal plane of the skin. Although vertical histopathology remains the diagnostic gold standard for most neoplastic and inflammatory skin diseases, HHSs represent a useful tool to validate the RCM features of some inflammatory disorders, including psoriasis, discoid lupus erythematosus, and eczema. The aim of the present review is to summarize the state of the art on the existing correlations between HHS and RCM in this field and to emphasize that RCM may represent a useful diagnostic tool to discriminate between diseases with similar clinical presentations.

Variation of Hair Follicle Counts among Different Scalp Areas: A Quantitative Histopathological Study

INTRODUCTION

Scalp biopsy is a standard method for the definitive diagnosis of alopecia. The hair count parameters of each scalp area remain unclear. This study aimed to determine hair count values at different scalp locations from histopathology and to establish reference values for each part of the scalp.

METHODS

We obtained biopsy specimens from the frontal, vertex, temporoparietal, and occipital areas of the scalps of normal deceased subjects. All specimens were evaluated for the number of follicular units, hair counts, hair types, and stages of the hair cycle.

RESULTS

In total, 240 specimens were collected from 60 cadavers. Across all scalp sites, the temporoparietal area showed the lowest mean hair count, number of follicular units, terminal and vellus hairs, and terminal-to-vellus hair ratio. The average anagen-to-telogen hair ratio was comparable across all scalp sites. This study did not observe a significant association of hair parameters with gender differences or increasing age in all scalp areas.

CONCLUSIONS

The present study revealed the diversity of the hair index among different scalp areas and suggested that normal hair count values should be separately standardized on each scalp region. Our findings may provide useful reference values for the histopathological evaluation of hair disorders in Asians.

Correlation Between In Vivo Reflectance Confocal Microscopy and Horizontal Histopathology in Skin Cancer: A Review

In dermatopathological daily practice, vertical histopathology sections are classically used to analyze skin biopsies. Conversely, horizontal histopathological sections are currently used for the diagnosis of some types of alopecia. In the last years the morphological findings obtained by horizontal histopathology have been correlated to those obtained by in vivo reflectance confocal microscopy which provides the same “point of view” of the skin. This review paper emphasizes the strong matching and correlation between reflectance confocal microscopy images and horizontal histopathology in cutaneous neoplasms, further demonstrating the strong reliability of this innovative, non-invasive technique in the management of skin tumors.