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Lentigines
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). Because of this characteristic feature, the adjective "lentiginous" is used to describe other skin lesions that similarly proliferate linearly within the basal cell layer.''Random House Webster's Unabridged Dictionary.'' Random House, Inc. 2001. p. 1101. .''Robbins and Cotran Pathologic Basis of Disease'' Elsevier. 2005. p. 1232. . Diagnosis Conditions characterized by lentigines include: * Lentigo simplex * Solar lentigo (Liver spots) * PUVA lentigines * Ink spot lentigo * LEOPARD syndrome * Mucosal lentig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LEOPARD Syndrome
Noonan syndrome with multiple lentigines (NSML) which is part of a group called Ras/MAPK pathway syndromes, is a rare autosomal dominant, multisystem disease caused by a mutation in the protein tyrosine phosphatase, non-receptor type 11 gene (''PTPN11''). The disease is a complex of features, mostly involving the skin, skeletal and cardiovascular systems, which may or may not be present in all patients. The nature of how the mutation causes each of the condition's symptoms is not well known; however, research is ongoing. It is a RASopathy. Noonan syndrome with multiple lentigines is caused by a different missense mutation of the same gene. Noonan syndrome is fairly common (1:1,000 to 1:2,500 live births), and neurofibromatosis 1 (which was once thought to be related to NSML) is also common (1:3500); however, no epidemiological data exists for NSML. Signs and symptoms An alternative name of the condition, LEOPARD syndrome, is a mnemonic, originally coined in 1969, as the condition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Skin Diseases
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square metres, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin.Burns, Tony; ''et al''. (2006) ''Rook's Textbook of Dermatology CD-ROM''. Wiley-Blackwell. . Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying mesoderm that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carney Complex
Carney complex and its subsets LAMB syndrome and NAME syndrome are autosomal dominant conditions comprising myxomas of the heart and skin, hyperpigmentation of the skin (lentiginosis), and endocrine overactivity. It is distinct from Carney's triad. Approximately 7% of all cardiac myxomas are associated with Carney complex. Presentation The spotty skin pigmentation and lentigines occur most commonly on the face, especially on the lips, eyelids, conjunctiva and oral mucosa. Cardiac myxomas may lead to embolic strokes and heart failure and may present with fever, joint pain, shortness of breath, diastolic rumble and tumor plop. Myxomas may also occur outside the heart, usually in the skin and breast. Endocrine tumors may manifest as disorders such as Cushing syndrome. The most common endocrine gland manifestation is an ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). The LAMB acronym refers to lentigines, atrial myxomas, and blu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lentigo Maligna Melanoma
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. 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. Presentation 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. Diagnosis The first problem is difficulty. As lentigo malignas often present on severely sun d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generalized Lentiginosis
Generalized lentiginosis is a cutaneous condition that will occasionally present without other associated abnormalities. It may be caused by carney complex, Noonan syndrome with multiple lentigines or Peutz–Jeghers syndrome. See also * Lentigo * Skin lesion A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of th ... References External links Melanocytic nevi and neoplasms {{Cutaneous-condition-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freckle
Freckles are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion. Freckles do not have an increased number of the melanin-producing cells, or melanocytes, but instead have melanocytes that overproduce melanin granules (melanosomes) changing the coloration of the outer skin cells (keratinocytes). As such, freckles are different from lentigines and moles, which are caused by accumulation of melanocytes in a small area. Freckles can appear on all types of skin tones. Of the six Fitzpatrick skin types, they are most common on skin tones 1 and 2, which usually belong to North Europeans. However, it can also be found on people all over the world. Biology The formation of freckles is caused by exposure to sunlight. The exposure to UV-B radiation activates melanocytes to increase melanin production, which can cause freckles to become darker and more visible. This means that one who has never developed freckles may develop them su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freckles
Freckles are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion. Freckles do not have an increased number of the melanin-producing cells, or melanocytes, but instead have melanocytes that overproduce melanin granules (melanosomes) changing the coloration of the outer skin cells (keratinocytes). As such, freckles are different from lentigines and moles, which are caused by accumulation of melanocytes in a small area. Freckles can appear on all types of skin tones. Of the six Fitzpatrick skin types, they are most common on skin tones 1 and 2, which usually belong to North Europeans. However, it can also be found on people all over the world. Biology The formation of freckles is caused by exposure to sunlight. The exposure to UV-B radiation activates melanocytes to increase melanin production, which can cause freckles to become darker and more visible. This means that one who has never developed freckles may develop them su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lentigo Maligna
Lentigo maligna is where melanocyte cells have become malignant and grow continuously along the stratum basale of the skin, but have not Invasion (cancer), 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. 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. The word lentiginous comes from the latin for freckle. Relation to melanoma 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrofacial Lentiginosis
Centrofacial lentiginosis is a cutaneous condition characterized by lentigines on the nose and adjacent cheeks. The condition is associated with sacral hypertrichosis, developmental delay, seizures, absent middle incisors, skeletal, abnormalities, dwarfism, endocrine dysfunction and congenital mitral valve stenosis.2 See also * Lentigo * Skin lesion A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of th ... References Melanocytic nevi and neoplasms 2. Bolognia, Jean, et al. ''Dermatology''. Elsevier, 2018. {{Cutaneous-condition-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inherited Patterned Lentiginosis In Black Persons
Inherited patterned lentiginosis is an inherited skin condition that results in widespread small, flat areas of more-pigmented skin with clearly defined borders, generally noticed when the affected person is an infant or young child. The inheritance pattern is autosomal dominant, and organs other than the skin are not affected; therefore, it is distinct from Carney complex Carney complex and its subsets LAMB syndrome and NAME syndrome are autosomal dominant conditions comprising myxomas of the heart and skin, hyperpigmentation of the skin (lentiginosis), and endocrine overactivity. It is distinct from Carney's tr .... References External links Melanocytic nevi and neoplasms {{Cutaneous-condition-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Unilateral Lentiginosis
Partial unilateral lentiginosis is a cutaneous condition characterized by lentigines located on only one half of the body. See also * Lentigo * List of cutaneous conditions References Melanocytic nevi and neoplasms {{Cutaneous-condition-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucosal Lentigines
Mucosal lentigines is a cutaneous condition characterized by light brown macules on mucosal surfaces. See also * Lentigo * Skin lesion A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of th ... References Melanocytic nevi and neoplasms {{Cutaneous-condition-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
