Avaliação quantitativa em cortes histológicos transversais do couro cabeludo

Abstract

BACKGROUND -Punch-biopsy is a great tool for the diagnosis of scalp disorders, however experience is required for the dermatopathologist. Recognizing the standard structures found in normal scalp is very helpful in this aspect. OBJECTIVE -The goal of this study was to determine quantitative data considering normal structures on the scalp of white adults. METHODS -Twenty necropsies were followed by eighty 4mm-punch biopsies of clinically normal scalp. Samples were evaluated by transverse sections. RESULTS -Scalp fragments from white adults, age 21 to 78, demonstrated (medians): 16.5 (12.0-23.0) total follicles; 8.0 (6.0-9.0) follicular units; 15.0 (10.0-20.0) terminal follicles; 1.0 (0.0-2.0) vellus follicle; and 1.0 (0.0-2.5) fibrous tract. Considering the hair cycle phase: 92.2% were in anagen; 1.6% in catagen and 6.2% in telogen. CONCLUSION -Comparing the results, male samples demonstrated fewer follicular units, total and telogen follicles, and higher number of total follicles and fibrous tracts on frontal and vertex area. Keywords: Alopecia; Dermatology; Hair follicle; Histology; Scalp 16,5 (12-23) folículos totais; oito (6-9) unidades foliculares; 15 (10-20) folículos terminais; um (0-2) folículo velo; um (0-2,5) Resumo: FUNDAMENTOS -A biópsia por punch é de grande auxílio no diagnóstico das doenças do couro cabeludo quando avaliada por patologista experiente. O conhecimento das estruturas encontradas no couro cabeludo normal facilita o diagnóstico histopatológico nessa área tão complexa da dermatopatologia. OBJETIVO -Determinar dados quantitativos normais do couro cabeludo de adultos brancos. MÉTODOS -Em 20 necrópsias, 80 fragmentos de couro cabeludo clinicamente normal foram obtidos por punch 4mm. As amostras foram avaliadas em cortes transversais. RESULTADOS -Em fragmentos obtidos de adultos brancos, com idade variando entre 21 e 78 anos, foi possível observar (medianas):

Evaluation of Hair Density and Hair Diameter in the Adult Thai Population Using Quantitative Trichoscopic Analysis

“…In that study, the density was the greatest in the frontal area and lowest in the temporal area. Another similar research study from Brazil included specimens from the vertex area and displayed similar findings with lower values, and their greatest parameters were observed at the vertex area [6]. Previous studies using automated phototrichograms revealed that the highest hair density was in the midscalp area, while the parietal area presented the lowest hair density [11,15].…”

“…Previous studies using scalp biopsy suggested that hair density and diameter varied at different sites of the scalp [5,6], and this has been confirmed by several research studies using computer-assisted phototrichograms [7][8][9][10][11]. Another factor reported to affect hair density and hair diameter is aging.…”

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

“…In contrast, the temporoparietal area presented the lowest number of follicular units and total hair count. This pattern of variation was consistent with the results from a study of scalp biopsies by Mulinari-Brenner et al [11] as well as previous studies that utilized quantitative trichoscopic analysis [11, 21-26]. Another study of scalp biopsies from Taiwanese individuals also acknowledged the differences in parameters across different scalp sites, but the number of follicular units and total hairs was the highest in the frontal area, whereas the lowest values were observed in the temporal area [16].…”

Evaluation of Scalp Hair Density and Diameter in the Arab Population: Clinical Office-Based Phototrichogram Analysis

“…Similar findings to ours were reported in previous studies in which the diameter and density of hair varied at different sites of the scalp; however, these studies reported such findings by using scalp biopsy. 12,13 This may suggest that further studies are needed comparing the accuracy of tools used to assess hair diameter and density. These findings were also confirmed by other studies that used computer-assisted phototrichograms, [14][15][16] which were similar to our study regarding findings and the tool used.…”