Search results for "pigmentation"

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…

Oral mucosal lesions in a Chilean elderly population: A retrospective study with a systematic review from thirteen countries.

2016

Background The oral examination is an essential part of the multidisciplinary medical care in elderly people. Oral mucosal lesions and normal variations of oral anatomy (OMLs) are very common in this people, but few studies have examined the frequency and prevalence of these conditions worldwide and less in Chile. The aim of this research was to evaluate the frequency of OMLs in a Chilean elderly population. Material and methods It was conducted a retrospective study (Talca, Chile). Two hundred seventy-seven OMLs were classified in groups and anatomical sites. In order to contextualize our numbers, we made a systematic review using Publish or Perish software, Google Scholar and InteractiVen…

Progressively fading asymptomatic brownish macules

2010

Skelettveränderungen bei Frühgeborenen mit Kupfermangel

1991

We describe 5 preterm infants (25th to 30th week of gestation) suffering from alimentary copper deficiency. The diagnosis was confirmed by low serum copper and caeruloplasmin concentrations. Characteristic clinical findings were repeated apnoeic attacks, hypopigmentation of skin and hair, anaemia, neutropenia and leucopenia refractory to other therapy, as well as increasing serum alkaline phosphatase activity in the first month of life. Starting in the 3rd to 12th week of life the radiographic findings were general skeletal osteoporosis and retardation, metaphyseal radiodense lines, irregular metaphyses, cupping and spurring of the metaphyses, followed by multiple fractures and subperiostea…

Histology and Fine Structure of the Iris and Outflow System Following Latanoprost Therapy

2002

Latanoprost therapy can lead to iris darkening in susceptible individuals, particularly those with hazel eyes. Concerns have been raised about whether latanoprost, and for that matter other prostanoids, may have a harmful effect on the iris. In addition, it is unknown whether latanoprost causes increased pigmentation of the outflow pathways that might eventually lead to blockage and a type of pigmentary glaucoma. The present study summarizes findings from the authors' own laboratories on the effects of latanoprost as seen by light and electron microscopy of the iris and outflow tissues and reviews the as yet limited, relevant literature. The findings support the proposal that latanoprost-in…

Responses to ultraviolet radiation in larval pike, Esox lucius, of two origins and ages

2007

Ultraviolet radiation (UVR)-induced mortality and behavioural disorder were studied in larval northern pike of two origins and ages. Newly hatched larvae of two differently coloured populations and six-day-old larvae of one population were exposed to four fluence rates of UVR, resulting in total doses from 11.5 to 63 kJ m–2, and monitored for mortality and behaviour. The rate of mortality and the severity of behavioural disorder differed by origin and age of the animals, but the effect was fluence-rate dependent. Total melanin concentration of newly hatched larvae was measured to assess if sensitivity to UVR correlated with pigmentation, but no differences in melanin concentration between l…

Znaczenie roślinnych i syntetycznych składników aktywnych we wspomaganiu procesu depigmentacji skóry

2021

Melanogenesis is a process catalyzed by tyrosinase enzyme leading to synthesis of two types of pigment in the skin: black-brown eumelanin and red-yellow pheomelanin. Pheomelanin is synthesized in the second stage of melanosome maturation, while eumelanin-synthesizing melanosomes are inactive. The black-brown pigment is produced in the third stage of melanosome development. The last, fourth stage of melanosome maturation is characterized by low tyrosinase activity, which reflects the low pigment production in the skin. The process of skin pigment production (melanogenesis) is mainly regulated by solar radiation, hormones and other endo- and exogenous factors. Over- stimulated melanogenesis l…