Lentigo simplex is the most common form of lentigo. A single lesion or multiple lesions (lentigines) may be present at birth or more commonly first develop in early childhood. Lentigo simplex is not induced by sun exposure, and it is not associated with any medical diseases or conditions. It is also referred to as simple lentigo and juvenile lentigo.
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Lentigo maligna is a histopathological variant of melanoma in situ. Lentigo maligna is sometimes classified as a very early melanoma, and sometimes as a precursor to melanoma. When malignant melanocytes from a lentigo maligna have invaded below the epidermis, the condition is termed lentigo maligna melanoma. Last Update: May 18, 2019.
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A few pathologists do not consider lentigo maligna to be a melanoma at all, but a precursor to melanomas. Once a lentigo maligna becomes a lentigo maligna melanoma, it is treated as if it were an invasive melanoma.
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Lentigo maligna melanoma is a melanoma that has evolved from a lentigo maligna, as seen as a lentigo maligna with melanoma cells invading below the boundaries of the epidermis. Last Update: May 18, 2019. They are usually found on chronically sun damaged skin such as the face and the forearms of the elderly. Lentigo maligna is the non-invasive skin growth that some pathologists consider to be a melanoma-in-situ.
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A melanoma in situ has not invaded beyond the basement membrane, whereas an invasive melanoma has spread beyond it. Some histopathological types of melanoma are inherently invasive, including nodular melanoma and lentigo maligna melanoma, where the in situ counterpart to lentigo maligna melanoma is lentigo maligna. Lentigo maligna is sometimes classified as a very early melanoma, and sometimes a precursor to melanoma. Superficial spreading melanomas and acral lentiginous melanomas can be either in situ or invasive, Topic Completed: 1 May 2013.
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First dilemma in diagnosis is recognition. As lentigo malignas often present on severely sun damaged skin, it is frequently found amongst numerous pigmented lesions – thin seborrheic keratoses, lentigo senilis, lentigines. It is difficult to distinguish these lesions with the naked eye alone, and even with some difficulty using dermatoscopy. As the lentigo maligna is often very large, it often merges with, or encompasses other skin tumors – such as lentigines, melanocytic nevi, and seborrheic keratosis.
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Lentigo is a genus of sea snails, marine gastropod mollusks in the family Strombidae, the true conchs.
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Lentigo maligna is where melanocyte cells have become malignant and grow continuously along the stratum basale of the skin, but have not invaded below the epidermis. Lentigo maligna is not the same as lentigo maligna melanoma, as detailed below. It typically progresses very slowly and can remain in a non- invasive form for years. It is normally found in the elderly (peak incidence in the 9th decade), on skin areas with high levels of sun exposure like the face and forearms.
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Lentigo pipus, common name : the Elegant Conch, is a species of Conch sea snail, a marine gastropod mollusk in the family Strombidae, the true conchs.
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Ink spot lentigo is a cutaneous condition characterized by skin lesions commonly occurring on the shoulders. These lesions often cause alarm but are benign. They are an indication of excessive sun exposure so although ink spot lentigo is not premalignant, people with several of them maybe at increased risk of skin cancer due to UV damage. For a safe diagnosis, they must be flat.
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Lentigo lentiginosus, common name the silver conch, is a species of medium- sized sea snail, a marine gastropod mollusk in the family Strombidae, the true conchs.
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Treatment depends on the thickness of the invasive component of the lentigo maligna. Treatment is essentially identical to other melanomas of the same thickness and stage.
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Incidence of evolution to lentigo maligna melanoma is low, about 2.2% to 5% in elderly patients. It is also known as "Hutchinson's melanotic freckle". This is named for Jonathan Hutchinson.J. Hutchinson.
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The flesh of Lentigo lentiginosus is edible, and it is locally collected for food. The shell is used in shellcraft, and is commonly sold in local markets around the central Philippines.
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A live scorpion conch (Lambis scorpius) in Mayotte. One can see the eyes as well as the scythe-shaped operculum. Live Conomurex decorus in La Réunion. Live Lentigo lentiginosus in La Réunion.
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An invasive tumor arising from a classical lentigo maligna. Usually a darkly pigmented raised papule or nodule, arising from a patch of irregularly pigmented flat brown to dark brown lesion of sun exposed skin of the face or arms in an elderly patient.
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Liver spots (also known as age spot, solar lentigo, "lentigo senilis", "old age spot", "senile freckle") are blemishes on the skin associated with aging and exposure to ultraviolet radiation from the sun. They range in color from light brown to red or black and are located in areas most often exposed to the sun, particularly the hands, face, shoulders, arms and forehead, and the scalp if bald. The spots derive their name from the fact that they were once incorrectly believed to be caused by liver problems, but they are physiologically unrelated to the liver, save for a similar color.Karen J. Carlson, Stephanie A. Eisenstat, Terra Diane Ziporyn, The new Harvard guide to women's health, Harvard University Press, 2004, p. 337.
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Lentigines are distinguished from freckles (ephelis) based on the proliferation of melanocytes. Freckles have a relatively normal number of melanocytes but an increased amount of melanin. A lentigo has an increased number of melanocytes. Freckles will increase in number and darkness with sunlight exposure, whereas lentigines will stay stable in their color regardless of sunlight exposure.
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Lentigo lentiginosus is widespread in the Indo-Pacific, from East Africa, including Aldabra, Madagascar, Mauritius and Tanzania to eastern Polynesia, and also in southern Japan and northern Australia.Poutiers, J. M. (1998). Gastropods in: FAO Species Identification Guide for Fishery Purposes: The living marine resources of the Western Central Pacific Volume 1. Seaweeds, corals, bivalves and gastropods.
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Micrograph of a seborrheic keratosis (H&E; stain, scanning magnification) Visual diagnosis is made by the "stuck on" appearance, horny pearls or cysts embedded in the structure. Darkly pigmented lesions can be challenging to distinguish from nodular melanomas. Furthermore, thin seborrheic keratoses on facial skin can be very difficult to differentiate from lentigo maligna even with dermatoscopy. Clinically, epidermal nevi are similar to seborrheic keratoses in appearance.
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Scar 13 days after excision of coloured patch about 10mm square with 5mm margins from 1cm to right of base of nose. Length of incision required for skin flap to cover excision site. Scar should lighten and become finer for up to further 6 months if protected from sun. The best treatment of lentigo maligna is not clear as it has not been well studied.
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Its stromboid notch, though not as conspicuous as observed in many species that used to belong to Strombus (such as Lentigo lentiginosus), is deep and easily distinguished. The interior may be slightly lirate. The external color of the shell can be either white with an orange, brown/tan pattern of blotches, or completely brown/white. The interior is usually colored strong orange, red or pink, and the inner lip border is black or chocolate brown.
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A lentigo () (plural lentigines, ) is a small pigmented spot on the skin with a clearly defined edge, surrounded by normal-appearing skin. It is a harmless (benign) hyperplasia of melanocytes which is linear in its spread. This means the hyperplasia of melanocytes is restricted to the cell layer directly above the basement membrane of the epidermis where melanocytes normally reside. This is in contrast to the "nests" of multi-layer melanocytes found in moles (melanocytic nevi).
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Pliny gave a fanciful derivation from Bos (ox) and taurus (bull), because the bittern's call resembles the bellowing of a bull. The species name lentiginosus is Latin for "freckled", from lentigo, "freckle", and refers to the speckled plumage. Many of the folk names are given for its distinctive call; In his book on the common names of American birds, Ernest Choate lists "bog bumper" and "stake driver", and other vernacular names include "thunder pumper" and "bog bull".
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The preferred method of diagnosis is by using a shave biopsy because punch biopsies give up to an 80% false negative rate. While one section of the tumor might show benign melanocytic nevus, another section might show features concerning of severe cellular atypia. When cellular atypia is noted, a pathologist might indicate that the entire lesion should be removed. It is at this point that one can comfortably remove the entire lesion, thus confirming the final diagnosis of lentigo maligna.
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Margin control (peripheral margins) is necessary to eliminate the false negative errors. If bread loafing is used, distances from sections should approach 0.1 mm to assure that the method approaches complete margin control. A meta-analysis of the literature in 2014 found no randomized controlled trials of surgical interventions to treat lentigo maligna or melanoma in-situ, even though surgery is the most widely used treatment. Mohs surgery has been done with cure rate reported to be as low as 77%, and as high as 95% by another author.
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Hereditary gain-of-function mutations of c-Raf are implicated in some rare, but severe syndromes. Most of these mutations involve single amino acid changes at one of the two 14-3-3 binding motifs. Mutation of c-Raf is one of the possible causes of Noonan syndrome: affected individuals have congenital heart defects, short and dysmorphic stature and several other deformities. Similar mutations in c-Raf can also cause a related condition, termed LEOPARD syndrome (Lentigo, Electrocardiographic abnormalities, Ocular hypertelorism, Pulmonary stenosis, Abnormal genitalia, Retarded growth, Deafness), with a complex association of defects.
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Histology slide of a solar lentigo Differently from the melanotic nevi and the verrucous nevi on the skin, age spots change in color and in shape with time. Michelitsch and Michelitsch propose an hypothesis inspired by their misrepair-accumulation aging theory for the development of age spots. They propose that aged basal cells contain lipofuscin bodies cannot be removed and might promote the aging of neighboring, generating a feedback loop whereby more and more neighbor cells become aged and lipofuscin-containing. Such cells might then aggregate into a spot with an irregular shape.
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If the defect is small and superficial it can be resurfaced with a skin graft or it can heal by secondary intention. Limited alar defects can be resurfaced using a nasolabial flap, however, the amount of tissue available from the nasolabial area is limited and the flap is thicker, less vascular, and hair bearing in males. Nasal defects mostly result from excision of (malignant) skin tumours as basal cell carcinoma, squamous cell carcinoma, malignant melanoma, keratoacanthoma, lentigo maligna, lymphoma, and sweat gland carcinoma.Mureau MA, Moolenburgh SE, Levendag PC, Hofer SO. Aesthetic and functional outcome following nasal reconstruction.
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They propose that the protruding of a flat spot is a result of the death of aged cells in the spot and release of lipofuscin bodies. The aggregating cells would form a capsule, and the dense lipofuscin bodies make the protruding spot soft and dark in color. However, this proposal appeared as a preprint in 2015, has little direct empirical support, and has never been published in a peer reviewed journal. Another group has reported that "age spots" taken from human skin biopsies of patients facial senile lentigo of Fitzpatrick skin type III or IV aged 55-62 are enriched with senescent fibroblasts compared to surrounding skin.
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The "double scalpel" peripheral margin controlled excision method approximates the Mohs method in margin control, but requires a pathologist intimately familiar with the complexity of managing the vertical margin on the thin peripheral sections and staining methods. Some melanocytic nevi, and melanoma-in-situ (lentigo maligna) have resolved with an experimental treatment, imiquimod (Aldara) topical cream, an immune enhancing agent. Some dermasurgeons are combining the 2 methods: surgically excising the cancer and then treating the area with Aldara cream postoperatively for three months. While some studies have suggested the adjuvant use of topical tazarotene, the current evidence is insufficient to recommend it and suggests that it increases topical inflammation, leading to lower patient compliance.
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"Clark's Classification" of melanoma Together with Martin Mihm, Clark described histogenic types of melanoma which differ in their epidemiology, as well as their clinical and histological appearance. The four major categories of Lentigo Maligna Melanoma, Superficial Spreading Melanoma, Nodular Melanoma, and Acral Lentiginous Melanoma loosely correspond to more recent molecular classification of the disease. "Clark's level" and melanoma prognosis Clark correlated the microscopic appearance of the tumor with careful followup of the progression of the tumor and the patient's outcome. From these studies he developed a five-part scale, based on the depth of penetration of the lesion from the epidermis into the dermis and down to the subcutaneous tissue, which can be used to predict the likely progression of the tumor and the prognosis for the patient.
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