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Melanocytic Hyperplasia (melanocytic + hyperplasia)
Selected AbstractsConcordant loss of heterozygosity of DNA repair gene, hOGG1, in melanoma in situ and atypical melanocytic hyperplasiaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2008Shayesteh Pashaei Background:, One major risk factor for cutaneous melanoma is chronic sun-exposure and oxidative stress. Among various oxidative DNA damages, 8-oxoquanine is the most abundant and is potentially mutagenic if not sufficiently repaired. The human 8-oxoquanine DNA glycosylase 1 (hOGG1) gene specifically repairs 8-oxoguanine, and this gene shows frequent loss of heterozygosity (LOH) in human tumors. In this study, we investigate whether hOGG1 LOH occurs in melanoma in situ (MIS) and adjacent atypical melanocytic hyperplasia (AMH). Methods:, Twelve skin biopsies with MIS and adjacent AMH were included. DNA samples derived from manual microdissection of tissues were subjected to polymerase chain reaction amplification using three fluorescent-labeled microsatellite makers, followed by fragment analysis. Results:, Five of 12 cases were informative for both telomeric (3S1297) and centromeric (3S1289 or 3S1300) markers, bordering the hOGG1 locus. Among them, four (80%) MIS and three (60%) AMH showed hOGG1 LOH at both markers. Conclusions:, These results shows that LOH at hOGG1 gene is associated with MIS and AMH and suggest that the hOGG1 gene may play a role in melanocytic tumor progression. [source] Melanocytic nevi are associated with neurofibromas in neurofibromatosis, type I, but not sporadic neurofibromas.JOURNAL OF CUTANEOUS PATHOLOGY, Issue 8 2005A study of 226 cases Background:, Neurofibromatosis, type 1, is associated with cutaneous melanin pigmentation, but an association with ordinary melanocytic nevi has not been described. Methods:, This retrospective case-control study was designed to see if neurofibromas in patients with neurofibromatosis, type 1 (NF-1) differ from sporadic neurofibromas (SN) in their incidence of associated melanocytic nevi and other histologic features. Slides from 114 NF-1 were compared with 112 SN and 300 intradermal melanocytic nevi (IDN). Results:, Small lentiginous melanocytic nevi were identified over 13 NF-1 (11%) but no SN (P = 0.0002). Compared with other NF-1, NF-1 with nevi were more frequently associated with melanocytic hyperplasia, giant melanosomes and diffuse neurofibroma (P < 0.03). Compared with SN, NF-1 were also more frequently associated with melanocytic hyperplasia, lentigo simplex-like changes, diffuse neurofibroma and plexiform neurofibroma (P < 0.001). Sebaceous hyperplasia (14%), dermal elastosis (9%), lipomatous change (8%), epithelial cysts (4%) and keratin granulomas or folliculitis (3%) were not significantly different in prevalence between NF-1, SN and the control group of IDN. Conclusions:, This study suggests that there is a difference in the potential for melanocytic proliferation in NF-1 compared with SN. NF-1, SN and IDN are associated with a similar range of incidental histologic changes. [source] Determination of Wavelength-Specific UV Protection Factors of Sunscreens in Intact Skin by EPR Measurement of UV-Induced Reactive Melanin RadicalPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007Leslie Lund ABSTRACT There remains an unmet need for skin tissue-based assays for the measurement of the UVA protection and efficacy of sunscreens. Here we describe development of a novel electron paramagnetic resonance assay that uses the photogeneration of reactive melanin radical as a measure of UV light penetration to melanocytes in situ in skin. We have used areas of focal melanocytic hyperplasia in the skin of Monodelphis domestica to model the human nevus. We show that we are able to use this assay to determine the monochromatic protection factors (mPF) of research and commercial sunscreens at specific narrow wavebands of UVB, UVA and blue visible light. Both commercial sunscreens, a sun protection factor (SPF) 4 and an SPF 30 product, had mPFs in the UVB range that correlated well with their claimed SPF. However, their mPF in the UVA ranges were only about one-third of claimed SPF. This technique can be used to design and assay sunscreens with optimally balanced UVA and UVB protection. [source] Pathology of conjunctival melanocytic neoplasmsACTA OPHTHALMOLOGICA, Issue 2008SE COUPLAND Purpose To describe the classification, grading and staging of conjunctival melanocytic proliferation. Methods We have audited our experience with conjunctival melanomas, using a novel mapping system and have found shortcomings in the current Tumour Node Metastasis (TNM) staging system. We have also reviewed our cases of intra-epithelial melanocytic neoplasia and confirmed other authors' impressions that conjunctival ,primary acquired melanosis with atypia' is histologically similar to cutaneous in situ melanoma. To improve objectivity in the reporting of conjunctival intra-epithelial melanocytic neoplasia, we propose a scoring system based on pattern of melanocytic infiltration, density of melanocytes & degree of cellular atypia. Results The term ,conjunctival melanosis' should be used only to describe the slit-lamp appearance of hyperpigmentation. Histologically, this abnormality should be categorized as ,hypermelanosis' or ,melanocytosis'. Hypermelanosis can either be primary or secondary to ocular or systemic disease. Benign melanocytosis comprises conjunctival melanocytic hyperplasia and naevi. Malignant melanocytosis is essentially melanoma, which is primary (in situ or invasive) or secondary (i.e., spreading to conjunctiva from adjacent tissues) or rarely metastatic. We suggest that the TNM staging system for conjunctival melanoma should be revised to: (1) include a Tis stage; (2) take account of superficial extent, invasion of adjacent tissues and caruncular involvement, in stages TI to TIII; and (3) to sub-categorize TIV disease so that there is better correlation with likely mortality. Conclusion We have revised the classification of conjunctival melanocytic proliferations & improved the grading and staging of melanoma. These developments should be useful in treatment & research. [source] | ||||||||||