Diagnostic accuracy measures for vertical and transverse scalp biopsies in cicatricial and non-cicatricial alopecias

Publication date: Available online 26 November 2017
Source:Dermatologica Sinica
Author(s): Kambiz Kamyab-Hesari, Nessa Aghazadeh, Pedram Nourmohammad-pour, Alireza Ghanadan, Azita Nikoo, Fatameh Gholamali, Mommad-Javad Nazemi, Ziba Rahbar
BackgroundScalp biopsy provides worthwhile diagnostic clues to diagnose the noncicatricial or cicatricial type of alopecia. Although a pair of vertically and horizontally sectioned pathology samples would be ideal, the diagnostic yield of vertical (V) or transverse (T) sectioning in different types of cicatricial and non-cicatricial alopecia is not studied. Also, when a single biopsy is submitted and/or the sample is not large enough for a combined V and T sectioning from a single specimen (such as HoVert technique), the decision to make the most appropriate sectioning would be challenging, specifically depending on the type of alopecia suspected clinically.MethodsA prospective study included 194 patients with two 4 mm-punch biopsies, one was sectioned vertically and the other horizontally. The V and T diagnoses were compared with the final diagnosis. The kappa coefficient of agreement, sensitivity, specificity, likelihood ratio (LR), diagnostic odd ratio (DOR) and concordance were estimated.ResultsThe most common types of alopecia were lichen planopilaris (62, 31%), androgenic alopecia (36, 18%) and central centrifugal cicatricial alopecia (26, 13%). The perifollicular inflammatory cell types, presence of pigmented cast and sebaceous hyperplasia were adequately detected in the in T (p < .001). The subcutaneous inflammation was better detected in V (p < .001). The T revealed higher diagnostic accuracy compared with V especially for noncicatricial alopecia (DOR, 157.5 vs. 21.2, p < .001).ConclusionsThe accurate diagnosis of alopecia requires both vertical and transverse section examination. Techniques providing both horizontal and vertical sections may be best suited for this indication. However, when expertise in such novel techniques are lacking, the higher diagnostic accuracy for T section justifies using T section for noncicatricial alopecia, if patient consented for single biopsy.