All articles starting with M
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Melanoma associated retinopathy
Melanoma associated retinopathy (MAR), ICD-11 9B71.40, is a rare paraneoplastic retinopathy of metastatic melanoma caused by TRPM1 autoantibodies against retinal ON-bipolar cells, causing night blindness, photopsias, field loss, and an electronegative ERG.
Melanoma of choroid
Melanoma of choroid (choroidal melanoma, uveal melanoma): malignant melanocyte tumor of the eye's choroid, the most common primary intraocular adult malignancy; treated by plaque brachytherapy or proton radiation, metastasizing mainly to the liver.
Melanoma of ciliary body
Melanoma of ciliary body, a uveal melanoma subtype (~6% of cases), arises behind the iris, is diagnosed late, carries poor prognosis, and is treated with plaque radiotherapy, proton beam, iridocyclectomy, or enucleation.
Melanoma of penis
Melanoma of penis (penile melanoma, ICD-11 2C81.1): rare melanoma of the penis, about 1.4% of penile cancers and under 0.1% of melanomas, usually on the glans, treated surgically with poor but improving survival.
Melanoma of skin
Melanoma of skin, or cutaneous melanoma, is a malignant tumor of pigment-producing melanocytes that causes most skin cancer deaths despite being about 1% of skin cancers.
Melanoma of soft tissue
Melanoma of soft tissue, or clear cell sarcoma (CCS), a rare melanocytic soft tissue sarcoma of tendons in young adults, defined by EWSR1-ATF1 fusion t(12;22), BRAF-negative, treated by wide resection.
Melanoma of vagina
Melanoma of the vagina (primary vaginal melanoma, ICD-11 2C71.1) is a rare mucosal melanoma of postmenopausal women, about 500 reported cases, NRAS-enriched with low KIT/BRAF, 5-year survival 5–25%, median disease-specific survival 19 months.
Melanoma of vulva
Melanoma of vulva (ICD-11 2C70.1) is a rare melanoma of vulvar pigment cells, about 1% of female melanomas, median age 68, KIT mutations, treated by wide local excision with sentinel node biopsy, 5-year survival about 50%.
Melanoma-associated antigen
Melanoma-associated antigen (MAGE) family: about 60 human genes sharing a MAGE homology domain; type I members (MAGE-A, -B, -C) are cancer-testis antigens first identified as MAGE-A1 in 1991, expressed in tumors, and targeted by immunotherapy including FDA-approved afami-cel.
Melanonychia
Melanonychia is brown or black discoloration of a fingernail or toenail, most often a vertical band (longitudinal melanonychia) caused by melanin deposited from the nail matrix.
Melanophage
Melanophage: a melanin-containing macrophage (Cell Ontology CL:0002060) that acquires pigment by phagocytosis of melanosomes, not synthesis; found in dermis, marks pigment incontinence, and dominates tumoral melanosis.
Melanophryniscus
Melanophryniscus (redbelly toads), a South American bufonid frog genus with 31 species, aposematic coloration, diet-sequestered alkaloid defenses, phytotelm or stream breeding, and 41% of assessed species threatened.
Melanopsidae
Melanopsidae, named by Henry and Arthur Adams in 1854, is a family of freshwater and brackish-water snails in the superfamily Cerithioidea, with the type genus Melanopsis.
Melanopsis
Melanopsis (Férussac, 1807) is a genus of freshwater melanopsid caenogastropod snails of the Mediterranean, North Africa, and Middle East, with a late Cretaceous brackish origin, Balkan early Miocene freshwater radiation, and threatened Moroccan species.
Melanoregulin
Melanoregulin (Mreg, gene MREG, also known as dilute suppressor protein homolog) is a small palmitoylated protein on melanosome membranes in melanocytes that promotes retrograde melanosome transport and negatively regulates melanosome transfer to keratinocytes.
Melanotan II
Melanotan II (MT-2, MT2) is a cyclic heptapeptide analogue of alpha-MSH, a non-selective melanocortin receptor agonist studied for tanning and erectile dysfunction, never approved as a drug and sold illegally as a tanning injection.
Melanotis
Melanotis (Bonaparte, 1850) is a genus of two blue mockingbirds in family Mimidae: the Blue Mockingbird (Melanotis caerulescens) of Mexico and the Blue-and-white Mockingbird (M. hypoleucus); basal mimid lineage, non-mimicking song.
Melanterite
Melanterite is a monoclinic sulfate mineral, ferrous sulfate heptahydrate (FeSO₄·7H₂O), formed mainly by oxidation of pyrite and marcasite in mine workings, and named in 1850 from the Greek for "copperas."
Melanthius (crater on Tethys)
Melanthius is a 250-km-wide impact crater, or basin, in the southern hemisphere of Saturn's moon Tethys, named in 1982 after the disloyal goatherd in Homer's Odyssey; it has a central peak cluster and is one of Tethys' two youngest basins.
Melantias
Melantias (Melantiana), ancient Thracian town near Büyükçekmece lagoon west of Constantinople, paired with Athyras; road station with imperial villa, 102 or 140 stadia from Byzantium; Valens marched from it before Adrianople.
Melarsoprol
Melarsoprol is a toxic arsenic-based drug, introduced in 1949, that treats the late stage of African sleeping sickness by injection, causing encephalopathy in 5 to 10% of patients.
Mélas
Mélas, also spelled Melas, is the name of several ancient rivers in the Barrington Atlas and Pleiades gazetteers, plus a historic quarter of Le Teil, Ardèche, France.
Melas Chasma
Melas Chasma, the widest segment of Valles Marineris on Mars, a 547 km canyon whose floor lies about 9 km below surrounding plains, with sulfate lake deposits, landslides, and proposed landing sites.
Melas Dorsa
Melas Dorsa is a 486.81 km ridge system (dorsa) on Mars, IAU-approved in 1976 from a classical Greek albedo feature name, located in the Thaumasia volcanic highlands about 250 km south of Melas Chasma, known for wrinkle ridges and a butterfly-ejecta crater imaged by Mars Express in 2012.
Melas Fossae
Melas Fossae is an IAU-approved system of tectonic troughs on Mars in the Thaumasia highlands near 26S, 72W, about 600 km across, named in 1985 from a classical albedo feature.
Melas Labes
Melas Labes is an IAU-named landslide feature (labēs) on Mars, 107.24 km across at -8.53°, 288.30°E on the south wall of Melas Chasma in Valles Marineris, approved in 1985 from a classical albedo feature.
Melas Mensa
Melas Mensa is a 245-km-diameter flat-topped feature (mensa) on Mars in Melas Chasma, central Valles Marineris, centered at 10.72°S, 285.85°E; a series of layered mesas with sulfate and aqueous minerals.
Melas River (Cilicia)
The Melas, Greek for "black", was a river on ancient Cilicia's western frontier that Pliny called the province's ancient boundary, now identified with the Manavgat-Su east of Side.
MELAS syndrome
MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) is a maternally inherited mitochondrial disease, usually from m.3243A>G in MT-TL1, causing stroke-like episodes, seizures, and lactic acidosis with no proven disease-specific therapy.
Melasma
Melasma, also called chloasma or mask of pregnancy, is a common acquired facial hyperpigmentation disorder driven by UV and visible light, hormones, and genetics, treated with photoprotection, triple-combination cream, and tranexamic acid.