amelanotic melanoma


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Related to amelanotic melanoma: Nodular melanoma

a·mel·a·not·ic mel·a·no·ma

an anaplastic melanoma consisting of cells derived from melanocytes but not forming melanin.

amelanotic melanoma

a melanoma that lacks melanin. See also melanoma.
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Amelanotic malignant melanoma

amelanotic melanoma

A rare, poorly differentiated form of melanoma, which arises in patients with a previous pigmented melanoma, in particular the desmoplastic melanomas.

amelanotic melanoma

Dermatology A rare, poorly differentiated form of melanoma, which occurs in Pts with a previous pigmented melanoma. See Melanoma, Regression.

amelanotic melanoma

neoplastic skin lesion not characterized by an increase in local skin pigmentation, and thus difficult to diagnose; characteristic of one-third of skin melanomas

melanoma

a tumor arising from melanocytes, dendritic cells of neuroectodermal origin, or melanoblasts. They are most common in the skin, eye and oral cavity of dogs and aged gray horses, but occur occasionally as congenital lesions in pigs, goats and cattle. An inherited, malignant melanoma is recorded in swordtail-platyfish hybrids.

amelanotic melanoma
one containing little or no melanin.
benign m's
usually pigmented plaques or nodules. Those with junctional activity are analogous to the human compound junctional nevus.
congenital melanoma of pigs
a single or multiple pigmented tumor of the skin or viscera that grows slowly and may metastasize. Spontaneous regression is common. An inherited form seen in Sinclair miniature pigs.
dermal melanoma
a tumor which arises from rests of melanocytes in the dermis, remnants of neural crest precursors. Pigmentation is variable. It is usually benign.
malignant melanoma
a malignant, rapidly growing, frequently ulcerated mass, consisting of either spindle cells or epithelioid cells or a mixture of the two, with a marked tendency to metastasize. The tumor cells may or may not (amelanotic) be pigmented. Although melanomas in pigs and cattle are usually benign and are not treated, those in horses, dogs, cats and occasional cases in sheep, goats and pigs are malignant. Called also nevocarcinoma.
References in periodicals archive ?
The framework then allowed the immunohistochemical diagnosis of metastatic amelanotic melanoma.
In the case of amelanotic melanoma or large melanoma that has broken through BruclTs membrane, the double circulation sign is noted (Figure 6).
In the case described by Ikeda et al, a patient with cutaneous amelanotic melanoma developed a metastatic tumor that involved the epiglottis; the tumor was successfully excised via an intraoral approach and KTP/532 laser surgery.
A potential clinical clue to the diagnosis of amelanotic melanoma may be the presence of a macular rim or spot of tan, gray, or brown pigmentation at the periphery of the lesion," Ms.
While only 5% of all melanoma cases are not among the major histopathologic subtypes, nearly 11% of the foot cases in the Loyola study were tumor variants, such as spindle cell or amelanotic melanoma.
Since the mRNA for MRP is frequently abundant even in amelanotic melanoma cells, the detection of mRNAs for tyrosinase, TRP-1, TRP-2, MART-1, HMB-45 using Northern blotting, reverse transcriptase-polymerase chain reaction, or in situ hybridization techniques can be helpful for the diagnosis of melanoma or for detection of metastatic disease.
The database and algorithm is being expanded to include basal and squamous cell carcinomas in addition to amelanotic melanomas.
While 1 study noted a possibly increased rate of S100-negative lesions among acral lentiginous melanomas (34) and our study reports 2 S100-negative lesions arising in acral lentiginous or amelanotic melanomas, most of our S100-negative lesions arose in superficial spreading or nodular melanomas.