GIANT CONGENITAL MELANOCYTIC NEVI – A RARE CASE REPORT

Giant congenital melanocytic nevi (GCMN) are the melanocytic lesions that arise due to the abnormal migration of melanoblasts during the embryogenesis, affecting approximately one in 500,000 live births. There is gain-of-function mutation in the NRAS gene is usually associated with GCMN, causing abnormal proliferation of embryonic melanoblasts that are usually present since birth with change in their morphological characteristics with time, and increasing in their size reaching upto a diameter ? 20 cm in adulthood. These are characterized by dark brown to black in color with irregular margins and having verrucous surfaces, with or without satellite lesions which are present beyond the periphery of the central lesion. Depending on their distribution these can be classified as bathing trunk, coat-sleeve, or stocking nevi. We hereby report a case of a sixteen year old female presenting with GCMN. The development of a malignant neoplasm on same lesion is only absolute indication for surgery in GCMN

Investigations into the culture condition for human epidermal melanoblasts in vitro / 中华皮肤科杂志

Objective To study the in vitro culture condition for melanoblasts from human foreskin tissue. Methods The skin tissue taken from foreskin of children was treated with 0.5% dispase Ⅱ to separate epidermis from dermis, then with trypsin to obtain single cell suspension, which was cultured in modified medium for melanoblasts, i.e., MCDB254 medium supplied with several cell growth factors. Finally, melanoblasts were obtained based on the difference of adhesion speed. The morphology and proliferation of cultured melanoblasts were observed under a light microscope. DOPA staining, immunostaining with anti- S-100 and -tyrosinase related protein 2 (TRP2) antibodies, and transmission electron microscopy were per- formed to identify the cultured melanoblasts. Results The cultured human melanocytes displayed a match-like shape, scattered arrangement, syrmnetric double poles, slim cell body, highly refractive nuclei; meanwhile, the melanoblasts exhibited plentiful cytoplasm, large volume, bipolar or irregular shape and clonal growth. Additionally, the melanocytes were positive for TRP2, S-100 and Dopa staining, while the melanoblasts were positive only for TRP2. Electron microscopy revealed the presence of mature melanin granules (stage Ⅲ-Ⅳ ) in melanocytes but immature melanin granules (stage Ⅰ ) in melanoblasts. Conclu- sion Stable pure culture of melanoblasts has been realized with the reformed medium, which may lay a foundation for the investigation into the mechanism of epidermal pigmentation.

In vitro effect of Fructus ligustri lucidi and its monomers on the migration of mouse melanoblasts / 中华皮肤科杂志

Objective To study the effects of Fructus ligustri lucidi and its monomers, tyrosol and oleanotic acid, on the migration of mouse melanoblast cell line (NCCmelb4M5). Methods Cultured NCCmelb4M5 cells were treated with Fructus ligustri lucidi (0.0625, 0.125, 0.25, 0.5, 2 mg/mL), tyrosol (0.02, 0.04, 0.08, 0.16, 0.8 mg/mL) and oleanolic acid (0.0625, 0.125, 0.25, 0.5, 2.5 mg/mL), respectively,for 48 hours followed by the detection of cell proliferation with MTT assay. The working concentration of the three drugs was determined according to the results of MTT assay. Scratch and transwell assays were performed to observe the effect of Fructus ligustri lucidi and its monomers at working concentration on the migration of NCCmelb4M5 cells. Results Based on the results of MTT assay, the working concentration of Fructus ligustri lucidi, tyrosol and oleanolic acid was determined at 0.125 mg/mL, 0.08 mg/mL and 0.0625 mg/mL respectively, and at these concentrations, these drugs exhibited a cytotoxity lower than that of absolute alcohol with no obvious stimulation of cell proliferation. Scratch and transwell assay revealed a promoting effect of both Fructus ligustri lucidi and tyrosol on melanoblast migration (P<0.05), while oleanolic acid had little effect on melanoblast migration. Conclusions The extract of Fructus ligustri lucidi has a significant stimulatory effect on the migration of mouse melanoblasts, and tyrosol may be an active component of Fructus ligustri lucidi associated with confirmative effect on migration of mouse melanoblasts.