| melanotic neuroectodermal tumour of infancy | A benign neoplasm of neuroectodermal origin that most often involves the anterior maxilla of infants in the first year of life. It presents clinically as a rapidly growing blue-black lesion producing a destructive radiolucency; histologically, it is characterised by small round undifferentiated tumour cells interspersed with larger polyhedral melanin-producing cells arranged in an alveolar configuration. Synonym: melanoameloblastoma, pigmented ameloblastoma, pigmented epulis, progonoma of jaw, retinal anlage tumour. (05 Mar 2000) |
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| neuroectodermal tumour, melanotic | A benign, rapidly growing, deeply pigmented tumour of the jaw and occasionally of other sites, consisting of an infiltrating mass of cells arranged in an alveolar pattern, and occurring almost exclusively in infants. Its source of origin is in dispute, the various theories giving rise to its several names. (12 Dec 1998) |
| tumor | 1. <oncology> An abnormal mass of tissue that results from excessive cell division that is uncontrolled and progressive, also called a neoplasm. Tumours perform no useful body function. They may be either benign (not cancerous) or malignant. 2. Swelling, one of the cardinal signs of inflammations, morbid enlargement. Origin: L. Tumere = to swell (12 May 1997) |
| tumor marker | <investigation, oncology> A substance in the body that usually indicates the presence of cancer. These markers are usually specific to certain types of cancer and are usually found in the blood or other tissue samples. Examples are alphafetoprotein (AFP), human chorionic gonadotropin, and lactate dehydrogenase (LDH). They may be indicators of tumour stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids. (18 Jul 2002) |
| tumor necrosis factor | <cytokine> Originally described as a tumour inhibiting factor in the blood of animals exposed to bacterial lipopolysaccharide or Bacille Calmette-Guerin. Preferentially kills tumour cells in vivo and in vitro, causes necrosis of certain transplanted tumours in mice and inhibits experimental metastases. Human Tumour Necrosis factor alpha is a protein of 157 amino acids and has a wide range of pro inflammatory actions. Usually considered a cytokine. Synonym: cachectin. Acronym: TNF (13 Nov 1997) |
| melanotic | 1. Pertaining to the presence, normal or pathologic, of melanin. 2. Relating to or characterised by melanosis. (05 Mar 2000) |
| melanotic carcinoma | <tumour> Obsolete term for melanoma. (05 Mar 2000) |
| melanotic freckle | A brown or black mottled, irregularly outlined, slowly enlarging lesion resembling a lentigo in which there are increased numbers of scattered atypical melanocytes in the epidermis, usually occurring on the face of older persons; after many years the dermis may be invaded and the lesion is then termed lentigo maligna melanoma. Synonym: Hutchinson's freckle, melanotic freckle. (05 Mar 2000) |
| melanotic pigment | <protein> Pigments largely of animal origin. High molecular weight polymers of indole quinone. Colours include black/brown, yellow, red and violet. Found in feathers, cuttle ink, human skin, hair and eyes and in cellular immune responses and wound healing in arthropods. (18 Nov 1997) |
| melanotic progonoma | A pigmented hairy nevus. (05 Mar 2000) |
| melanotic whitlow | <tumour> A melanoma beginning in the skin at the border of or beneath the nail. Synonym: melanotic whitlow. (05 Mar 2000) |
| primitive neuroectodermal tumour | A designation used to refer to a group of morphologically similar embryonal neoplasms that arise in intracranial and peripheral sites of the nervous system and which may show various degrees of cellular differentiation; includes medulloblastoma, pineoblastoma, etc. (05 Mar 2000) |
| primitive neuroectodermal tumours | A type of brain tumour. Prenatal diagnosis: diagnosis before birth. Methods for prenatal diagnosis include ultrasound (of the uterus, placenta and developing foetus), chorionic villus sampling to obtain tissue for chromosome or biochemical analysis, amniocentesis to obtain amniotic fluid for the analysis of chromosmes, enzymes, DNA, etc. A growing number of birth defects and diseases are now amenable to prenatal diagnosis. Also called antenatal diagnosis. (12 Dec 1998) |
| hutchinson's melanotic freckle | A cutaneous malignant melanoma found most often on the sun-exposed areas of the skin, especially the face, which begins as a circumscribed, macular patch of mottled pigmentation, showing shades of dark brown, tan, or black, and enlarges by lateral growth before dermal invasion occurs. This type is the slowest growing, has the least tendency to metastasize, and seems to be the least aggressive form of malignant melanoma. Patients are commonly in their sixth or seventh decade. (12 Dec 1998) |
| neuroectodermal | Relating to the neuroectoderm. (05 Mar 2000) |