Role of Wnt signaling in dermatofibroma induction phenomenon

Abstract Background Dermatofibroma (DF) is a common benign skin neoplasm. Induction above DF lesions, including follicular unit induction, is a frequently observed phenomenon. Wnt signaling is known to be critical in hair follicle morphogenesis. Our study assesses the role of Wnt signaling in DF induction by evaluating intracellular localization of β‐catenin in various types of DF induction. Methods Archived tissue collected between 1 October 1980 and 1 October 2013 was stained per protocol using hematoxylin and eosin and anti‐β‐catenin monoclonal antibody. Specimens were grouped into categories based on the presence or absence and type of induction. All specimens were scored for nuclear β‐catenin localization. Results Of 62 specimens, 42 (68%) showed induction while 20 (32%) showed none. Nuclear β‐catenin staining was detected in 23 (55%) of the induction and in none of the no‐induction specimens ( P ‐value < 0.001). Types of induction included: 15 (24%) follicular induction, 31 (50%) acanthosis, and 4 (6%) sebaceous induction. For follicular induction, 13 (87%) showed positive nuclear β‐catenin staining compared to 11 (35%) for acanthosis and 1 (25%) for sebaceous induction ( P ‐value = 0.002). Conclusion Our findings support the hypothesis that DFs promote an ectopic activation of Wnt pathway signaling in follicular induction phenomenon.