Split-skin grafting from the scalp: the hidden advantage.

BACKGROUND: Split-skin grafting is a routine reconstructive technique associated with large variation in practice. Grafts from the thigh, buttock, or abdomen take a long time to heal and may leave unpleasant, hypopigmented scars. Retrospective reports favor the scalp as a donor site in burn patients. OBJECTIVE: Evaluation of duration of healing, cosmetic outcome, and safety of split-skin grafting from the scalp in patients receiving dermatologic surgery. MATERIAL AND METHODS: One hundred sixty-six consecutive patients (85 men, 81 women) were treated for coverage of chronic leg ulcers or other large skin defects with a split-skin graft taken from the posterior scalp. Area and thickness of the graft, healing time, and adverse events were documented. RESULTS: Mean healing time until complete reepithelization was 5.4+/-1.0 days for a single harvest (median 5 days). No major complications occurred. Spotted alopecia was a rare event. Almost all (96.5%) of the patients would undergo split-skin harvesting from the occipital scalp again if needed. CONCLUSIONS: Advantages of the scalp as a donor site include rapidity of wound healing, low risk of complications, and excellent cosmetic results. The large number of hair follicles containing the epidermal stem cell pool can explain these advantages.

Phospho-ERK staining is a poor indicator of the mutational status of BRAF and NRAS in human melanoma.

Mutated BRAF and NRAS are suspected to contribute to melanomagenesis by activation of extracellular signal-regulated kinase (ERK). To test this notion, we analyzed the presence of phosphorylated ERK1/2 in 170 melanomas with established NRAS/BRAF mutational status and well-documented clinical follow-up by immunohistochemistry. Several notable observations were obtained: (i) phospho-ERK staining was very heterogeneous within the tumor; (ii) in most cases, ERK was phosphorylated in only a minority of tumor cells; (iii) the percentage of phospho-ERK-positive cells was not correlated with the mutational status of NRAS and/or BRAF; (iv) the Raf kinase inhibitor protein (RKIP) was expressed homogeneously in virtually all melanoma samples not reflecting the inhomogeneity of phospho-ERK; and, finally, (v) neither the portion of phospho-ERK-positive tumor cells nor the RKIP staining intensity showed any correlation to the clinical course of the patients. Furthermore, the ability of BRAF mutant melanoma cells to downregulate mitogen-activated protein kinase activation was shown in melanoma cell lines cultured at high densities or under nonadherent conditions. Our findings suggest that mitogen-activated protein kinase (MAPK) activity is subject to regulation even in BRAF/NRAS mutant melanoma cells and that high MAPK pathway signaling may be important only in distinct subsets of tumor cells.

Postnatal confirmation of prenatally diagnosed trisomy 20 mosaicism in a patient with linear and whorled nevoid hypermelanosis.

Linear and whorled nevoid hypermelanosis (LWNH) is characterized by hyperpigmented reticulate macules in a Blaschko linear arrangement without atrophy or preceding inflammation. Underlying chromosomal mosaicism was often assumed, but has been verified in only a few published cases. We report a 7-year-old boy with LWNH associated with congenital ventricular septal defect and psychomotor retardation. Prenatal chromosomal analysis of amniocytes revealed trisomy 20 mosaicism, which was not confirmed in peripheral blood lymphocytes after birth. Histologic sections of skin biopsy specimens taken at age 6 years showed hyperpigmentation of the basal epidermal layer with prominent melanocytes and isolated melanophages in the upper dermis. Cytogenetic analysis of cultured skin fibroblasts revealed an extra chromosome 20 in 5 of the 30 metaphases studied (17%). Mosaic trisomy 20 is one of the most common autosomal mosaicisms identified in amniocytes and is, as a rule, compatible with normal pregnancy outcome. In postnatal analysis of peripheral blood lymphocytes, an extra chromosome 20 could never be detected. However, when confirmed in skin fibroblasts, trisomy 20 mosaicism may be associated with systemic anomalies. The present case shows for the first time an association of LWNH with trisomy 20 mosaicism and emphasizes the importance of analyzing skin fibroblasts in cases of prenatally diagnosed trisomy 20.