Histopathological Evaluation of Scar Tissue and Adjacent Non-Involved Skin

Abstract

Background: Previous researches declared that scars are the end outcome of the natural healing and reparative process as a result of dermal fibrotic scar formation post inflammation. Few studies were conducted to explain the role of perilesional area in abnormal scar pathogenesis. Objective: To study the histopathological changes in different types of scars and adjacent apparently non-involved skin. Hopefully, this insight can set the route for newer therapeutic approaches. Patients and Methods: This prospective case control study was carried out on 30 participants divided into three groups. Group1 included ten keloid biopsies, Group2 included ten hypertrophic scar biopsies and Group3 included ten atrophic scar biopsies. Clinical assessment of scars was done. Skin biopsy specimens were taken from lesional and perilesional skin and sent to histopathology laboratory. Results: Increased epidermal thickening was significantly noted in 80% of perilesional specimens of keloid scar and that was significantly higher than lesional skin, while dermal fibroblasts/myofibroblasts were mildly increased in 80% of specimens and were associated with severe perivascular inflammatory infiltrates in 70% of perilesional specimens. Myofibroblasts/ fibroblasts and perivascular infiltrate were significantly higher in perilesional than lesional keloid skin. Epidermal thickening was significantly increased in all perilesional specimens of hypertrophic scar and was significantly higher than lesional skin. In dermis, hair follicles and sebaceous glands were identified in 100% of perilesional skin. Dermal cellularity was significantly mildly increased in 100% of perilesional specimens of atrophic and hypertrophic scars and both were significantly higher than normal skin. Conclusion: Perilesional area is a shadow area and may be a main player in abnormal scar pathogenesis and could be responsible for progression or regression of scar.