Utility of Elastic Stains and Polarised Microscopy in Cases of Lichen Planopilaris in Cicatricial Alopecia

Introduction: Primary alopecia is of two sub-types, namely, scarring and non-scarring. Scarring (cicatricial) alopecia targets the hair follicle unit and thus causes destruction of the hair follicle unit itself. On the other hand, in non-scarring alopecia, there is preservation of follicular units with no evidence of follicular drop-outs. Aims and Objectives: To study the elastic stain patterns and pattern of birefringence by polarised microcopy in cases of Lichen planopilaris (LPP). Materials and Methods: This retrospective study comprised 25 patients diagnosed with LPP in cicatricial alopecia at the Department of Pathology from January 2016 to June 2019. Verhoff’s Van Geison Elastin (VVG) stain was compiled as the presence and absence of perifollicular fibrosis. Positive and negative birefringence was noted in the fibrous tract by polarised microscopy. Observations and Results: Perifollicular fibrosis with loss of elastic fibres was detected in 88% cases (n = 22) cases, while elastic stains were non-contributory in 12% cases (n = 3). Concordant results with VVG and positive birefringence were obtained in 52% cases (n = 13). 36% cases (n = 9) cases showed perifollicular fibrosis on VVG stain but were not highlighted by birefringence. Three cases were not detected by either of these techniques. The sensitivity of VVG stain was 95.6%, while the specificity was 100%. The sensitivity of positive birefringence in the fibrous tract in detecting LPP was 56.5%, while the specificity was 100%. Conclusion: Elastic staining is a useful technique for evaluating LPP routine specimens with high sensitivity. Polarised microscopy has low sensitivity and high specificity in identifying cases of LPP. These techniques thus aid in diagnosing cases of irreversible hair loss and thus improve the treatment outcomes.