© 2004 The International Society of Dermatology International Journal of Dermatology 2004 1 doi: 10.1111/j.1365-4632.2004.02507.x Abstract Background Frontal fibrosing alopecia (FFA) is an acquired scarring alopecia currently considered a clinical variant of lichen planopilaris (LPP). Our purpose was to examine the clinicopathological features of FFA. In addition, we investigated the similarities and differences between FFA and LPP. Methods Biopsies from the scalp lesions of eight patients with FFA and eight patients with LPP were microscopically analyzed. Two cases of FFA and four cases of LPP were studied using direct immunofluorescence. Results In spite of the completely different clinical characteristics of FFA and LPP patients, the histopathological findings for the two entities were similar. Common microscopic findings for both FFA and LPP included an inflammatory lymphocytic infiltrate involving the isthmus and infundibulum of the hair follicles, the presence of apoptotic cells in the external root sheath, and a concentric fibrosis surrounding the hair follicles that resulted in their destruction with subsequent scarring alopecia. Biopsies taken from FFA patients showed less follicular inflammation and more apoptotic cells than those from LPP patients. In some cases of LPP, the inflammatory infiltrate involved the interfollicular epidermis, a finding never present in our FFA cases. Direct immunofluorescence was negative in the two cases of FFA studied and showed deposits of immunoglobulins and/or complement in two of the four LPP cases examined. Conclusions The characteristic findings for FFA were more prominent apoptosis and less inflammation than found in LPP, along with spared interfollicular epidermis. FFA cases showed a rather characteristic histopathological pattern, although we could not find any clear-cut histological differences between FFA and LPP. Blackwell Publishing, Ltd. Oxford, UK IJD International Journal of Dermatology 1365-4632 Blackwell Publishing Ltd, 2004 45 Report Frontal fibrosing alopecia versus lichen planopilaris Poblet et al. Frontal fibrosing alopecia versus lichen planopilaris: a clinicopathological study Enrique Poblet, MD, Francisco Jiménez, MD, Alejandro Pascual, MD, and Enric Piqué, MD From the Department of Pathology, Hospital General Universitario de Albacete, Albacete, Spain, Private Practice, Las Palmas de Gran Canaria, Canary Islands, Spain, and Hospital General de Lanzarote, Canary Islands, Spain Correspondence Francisco Jiménez, MD Calle Angel Guimerá, 2 Las Palmas de Gran Canaria 35003 Spain E-mail: fjimenez@clinicadelpelo.com Introduction Frontal fibrosing alopecia (FFA) is a progressive scarring alo- pecia first described by Kossard 1 in 1994. Patients are usually elderly postmenopausal women who present a symmetric recession of the frontal and temporal hairlines. The affected skin appears pale and atrophic, lacking follicular orifices. A common associated finding is a bilateral loss of the hair of the eyebrows. The course of this disease is slowly progressive, and medical therapies have not been efficacious in the majority of patients. Since its original description, numerous reports have appeared in the literature, 2–17 suggesting that FFA is more prevalent than originally thought. Most authors consider FFA as a clinically distinct variant of lichen planopilaris (LPP), based on the fact that their histolog- ical findings appear to be indistinguishable. Both entities show a lichenoid lymphocytic inflammatory infiltrate, peri- follicular fibrosis, and hair follicle destruction. It is thought that the destruction of the external root sheath at the level of the isthmus (where the stem cells are supposed to reside) is responsible for the nonreversible scarring type of alopecia. This comparative study of FFA and LPP was undertaken with the goal of determining whether there are histopathological differences between the two conditions that could allow a diagnosis to be made based solely on the histological picture. Materials and Methods The case records of seven women with FFA diagnosed in the Canary Islands and one woman with FFA diagnosed at the Hospital General Universitario de Albacete between 1998 and 2002 were reviewed. The clinical diagnosis was confirmed in all patients with scalp biopsies obtained from the affected areas. The biopsies were analyzed in vertical and horizontal sections, stained with hematoxylin-eosin, periodic acid Schiff (PAS) stain, and Masson’s trichrome stain. Two cases were analyzed with direct immunofluorescence for immunoglobulin A (IgA), IgG, IgM, C3 complement, and fibrinogen.