Why are Scars Pale? An Immunohistochemical Study Indicating Preservation of Melanocyte Number and Function in Surgical Scars
long-standing pale scars and gave consent for a 4 mm punch biopsy to The cosmetic eVect of many mature scars is largely due to their be taken from the scar. Eleven biopsies were taken from sun-protected paler appearance than the surrounding skin. The aim of the sites (chest 4; abdomen 5; thigh 2) and ve from sun-unprotected sites study was to identify whether melanocytes are present and (face 3; forearm 2). Subjects were skin type 2 or 3 and had not had functioning within pale scars.
... e scars. Cryosections from scar and normal signi cant recent sun exposure. In addition, in 6 of these volunteers, a 4 mm punch biopsy was also taken from adjacent normal skin tissue were stained with murine monoclonal antibodies mel-5, (within 3-5 cm of the scar). Ethical approval was granted by c-kit and NKI / beteb to detect melanocytes and precursor melan-Sunderland City Hospitals Trust ethics committee. Tissue was frozen ocytes. The mean number of mel-5 immunopositive melanocytes in embedding medium (OCT; Miles, Elkhart, USA), cut into 7 mmwithin scar tissue was similar to that seen in normal skin (26, thick sections and placed on Tespa coated glass slides (Sigma-Aldrich, SEM 3.5, versus 28.9, SEM 4.1, per 200 basal cells). Where St Louis, USA) for immunohistochemical and Masson-Fontana staining. paired samples were available, there was no statistically signi cant diVerence between scar tissue and adjacent skin (95% CI = Immunohistochemistry ± 7.8 to + 4.6, p = 0.53). Masson-Fontana stain for melanin was positive in both scar tissue and adjacent normal skin, with The sections were air-dried and acetone xed at 4°C for 10 min. These no evidence for diVerences in melanin transfer to keratinocytes. speci c monoclonal antibodies were used in the 10 unpaired samples Our results suggest that neither diVerences in melanocyte number (Table I ) . Mel-5 detects a 75-kDa pigment-associated glycoprotein found on normal melanocytes and melanoma cells (4). The c-kit nor melanogenic activity explain the appearance of scars. It detects a tyrosine kinase receptor found on melanocytes and mast would seem likely that a combination of both vascular and cells; interaction between mast cell growth factor and this receptor optical factors relating to dermal or epidermal characteristics regulates the migration of melanoblasts from the neural crest and are more important.