Search results for "PIGMENT"
showing 10 items of 626 documents
Evaluation of Skin Melanoma in Spectral Range 450-950 nm Using Principal Component Analysis
2013
Diagnostic potential of principal component analysis (PCA) of multi-spectral imaging data in the wavelength range 450-950 nm for distant skin melanoma recognition is discussed. Processing of the measured clinical data by means of PCA resulted in clear separation between malignant melanomas and pigmented nevi.
Hyperpigmentation of hard palate induced by chloroquine therapy
2017
The antimalarials are one of the most commonly prescribed drugs for conditions such as lupus erythematosus and rheumatoid arthritis, and the side effects, though infrequent, are well known. The antimalarial agent chloroquine diphosphate usually causes pigmentary changes in the oral mucosa characterized by a bluish-grey to black discolorations mainly in the hard palate. Considering only the hard palate hyperpigmentation caused by chloroquine, to the best of our knowledge, only 13 cases have been reported in the English language literature. We described an additional case of palate hyperpigmentation related to the chronic use of chloroquine diphosphate in a 60-year-old Mexican woman. Although…
Pharmacological Characterization of Loss of Function Mutations of the Human Melanocortin 1 Receptor That Are Associated with Red Hair
2004
Variation in skin color is the major host risk factor for melanoma and other forms of skin cancer. Individuals with red hair show an increased ratio of phaeomelanin to eumelanin in both hair and skin. This ratio is regulated by the melanocortin (MC) 1 receptor. There are several common point mutations in the human MC1 receptor that are overrepresented in North European red-heads, and in individuals with pale skin. In order to determine the functional significance of these mutations, we expressed the Asp84Glu, Val92Met, Arg163Gln, and Asp294His variants of the human MC1 receptors in eukaryotic cells and determined their ability to bind alpha-melanocyte stimulating hormone (MSH) peptides and …
Skin chromphore mapping by means of a modified video-microscope for skin malformation diagnosis
2013
Many spectral imaging devices are commercially available and used to detect certain skin pathology; however an alternative cost-efficient device can provide an advanced spectral analisys of skin. Multispectral device for diagnosis of pigmented skin lesions was developed and tested. Possibilities to map skin chromophores using a modified low-cost digital video-microscope is discussed. It was adapted for an advanced skin microscopy and used for detailed spectral analysis of skin. The device comprises CMOS digital imaging sensor, four-colour LED illumination system and image acquisition optics. The main goal is to obtain a set of spectral images of the skin area of interest for further convers…
Melanoma of the oral mucosa with cerebral metastasis: a clinical case
2005
Summary Oral melanoma (OM) is an infrequent neoplasia making up less than 1% of all melanomas, and which exhibits a much more aggressive behaviour than those found on the skin. We present a case of OM located on the hard palate, vestibular alveolar gingiva of the maxilla, and upper lip in a 75-year-old patient who developed a distant metastasis on the left parietal lobe. The advanced stage of the disease contraindicated any surgical intervention and it was decided to carry out palliative radiotherapy, but the patient died before treatment.
Descriptive Dermoscopic Study of Depigmentation in Melanocytic Nevi Without a Visible Halo
2011
Background and objectives: There are few cases described in the literature in which depigmentation of melanocytic nevi occurs without the appearance of halos. The aim of this study was to analyze the correlation between clinical and dermoscopic findings and to assess the usefulness of dermoscopy to identify possible markers of complete regression in melanocytic lesions. Materials and methods: A prospective, observational, descriptive study of 77 melanocytic lesions in 52 patients was undertaken over a 5-year period. Melanocytic lesions from patients who underwent periodic follow-up in the digital dermoscopy unit were analyzed if they had exhibited partial or total, permanent depigmentation …
Oral pigmented lesions: clinicopathologic features and review of the literature
2012
Diagnosis of pigmented lesions of the oral cavity and perioral tissues is challenging. Even though epidemiology may be of some help in orientating the clinician and even though some lesions may confidently be diagnosed on clinical grounds alone, the definitive diagnosis usually requires histopathologic evaluation. Oral pigmentation can be physiological or pathological, and exogenous or endogenous. Color, location, distribution, and duration as well as drugs use, family history, and change in pattern are important for the differential diagnosis. Dark or black pigmented lesions can be focal, multifocal or diffuse macules, including entities such as racial pigmentation, melanotic macule, melan…
Reticulate postinflammatory hyperpigmentation with band-like mucin deposition
1998
Background Mucinoses of the skin are a group of disorders sharing accumulation of mucin in the skin or hair follicles. Postinflammatory hyperpigmentation, with pigmentary incontinence, is due to loss of melanin from epidermal basal cells and its accumulation in dermal macrophages. Methods We describe clinicopathologic features of two patients presenting with the association of pigmentary incontinence with an unusual diffuse, band-like dermal deposition of mucin, clinically presenting with reticular pigmented macular lesions. Results Two patients were observed with asymptomatic, persistent, reticular, pigmented patches located in the flexures, thighs, neck and back. Histology showed melanoph…
Development of choroidal neovascularization following transpupillary thermotherapy (TTT) for a small malignant melanoma of the choroid at the posteri…
2010
Abstract Introduction The malignant melanoma of the choroid is the most common primary malignant intraocular tumor in adults. There are currently several methods available for the treatment of choroidal melanomas. Among others, hyperthermia represents a therapeutic approach in which infrared radiation is delivered through the dilated pupil, called “transpupillary thermotherapy (TTT)”. The method was initially assumed to cause only a few side effects but gradually more and more complications have been observed. The treatment is associated with a number of vascular responses, for example arterial and venous occlusions. However neovascularizations of the choroid have only been detected twice s…
Semi-automated non-invasive diagnostics method for melanoma differentiation from nevi and pigmented basal cell carcinomas
2017
The incidence of skin cancer is still increasing mostly in in industrialized countries with light- skinned people. Late tumour detection is the main reason of the high mortality associated with skin cancer. The accessibility of early diagnostics of skin cancer in Latvia is limited by several factors, such as high cost of dermatology services, long queues on state funded oncologist examinations, as well as inaccessibility of oncologists in the countryside regions - this is an actual clinical problem. The new strategies and guidelines for skin cancer early detection and post-surgical follow-up intend to realize the full body examination (FBE) by primary care physicians (general practitioners,…