Elastic Staining in Differentiating Between Follicular Streamers and Follicular Scars in Horizontal Scalp Biopsy Sections

Background: Accurate identification of follicular streamers versus follicular scars on horizontal scalp biopsy sections is important to differentiate between cicatricial and noncicatricial alopecias. However, distinguishing between them can be difficult especially in nonoptimal specimens. The utility of elastic Verhoeff–Van Gieson (EVG) stain in cicatricial alopecias has been described on vertical sections, but its evaluation on horizontal sections has not been performed. Methods: Sixty-four cicatricial alopecias (25 lichen planopilaris, 29 central centrifugal cicatricial alopecias, and 10 discoid lupus erythematosus) and 53 noncicatricial alopecias (34 androgenic alopecia, 8 telogen effluvium, and 11 alopecia areata) were identified, and EVG staining was performed on horizontal sections. Results: In follicular streamers, EVG highlighted an intact elastic network composed of delicate and thin elastic fibers circumferentially surrounding the angiofibrotic streamer without elastic network attenuation, loss, clumping, thickening, or recoil. In follicular scars, EVG demonstrated central attenuation and loss of the elastic network with peripheral clumping and recoil of elastic fibers. Conclusions: In cases where distinguishing between follicular streamers and scars is difficult, EVG may be a helpful adjunctive tool in this regard and aid in allowing better discrimination between cicatricial and noncicatricial alopecias.

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