Immunohistochemical Evaluation of Leptin Role in Skin Tags.

Skin tags (STs) are common benign dermal connective tissue neoplasms that are mainly composed of loose fibrous tissue. However, their exact etiology is not fully understood. Leptin is a major player in the biology and pathology of the skin and its appendages. It is linked to cell differentiation, proliferation, migration, and survival with pronounced effects on angiogenesis, blood flow, and tissue perfusion. This study aimed at investigating the possible role of leptin in STs pathogenesis and correlating its expression with different clinical and histopathological parameters. Using immunohistochemical techniques, we examined 90 subjects. These included 60 non-obese cases with STs and 30 age-, gender- and Body Mass Index-matched normal subjects as a control group. Leptin was overexpressed in STs compared with normal skin (p < .001). Nuclear and nucleocytoplasmic patterns were significantly associated with cases both in epidermis (p < .04) and dermis (p < .001). Higher epidermal leptin H score was significantly associated with female gender (p = .004) and haphazard collagen arrangement (p < .03). Higher dermal leptin H score was significantly associated with smooth skin tags (p = .01), dilated blood vessels (p = .04), presence of mast cells (MCs) (p = .002), presence of inflammatory cells (p = .004), and haphazard collagen arrangement (p < .001). In conclusion, leptin may play a role in STs pathogenesis through its effects on keratinocytes, fibroblasts and vascular endothelium. Further studies are recommended to clarify the molecular interplay between leptin and MCs in ST pathogenesis. Further studies are also needed to determine the significance of its nuclear expression.