melanoma

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Related to subungual melanoma: Acral lentiginous melanoma

melanoma:

see skin cancerskin cancer,
malignant tumor of the skin. The most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. Rarer forms include mycosis fungoides (a type of lymphoma) and Kaposi's sarcoma.
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Melanoma

 

melanoblastoma; a malignant tumor that consists of melanin-producing cells.

Factors conducive to the development of melanomas include injury and hormonal stimulation, especially during puberty. Melanomas generally occur on the skin; less often, they appear on the retina, pia mater, nasopharynx, larynx, esophagus, and mucosa of the intestine and other organs. Melanomas usually develop at the site of pigmented or depigmented birthmarks, but they may also appear elsewhere. The process starts with a barely perceptible, painless tumor on the skin, sometimes resembling a wart, which gradually becomes dark brown or black. Occasionally, it ulcerates and bleeds. In case of injury, the tumor may enlarge quickly and become tuberous, dense at the base, and stiffer. The regional lymph nodes enlarge. The initial signs that a melanoma is developing at the site of a birthmark are the birthmark’s enlargement, an intensification or reduction in its pigmentation, and the appearance of a red rim around it. Treatment involves prompt surgical intervention, based on early diagnosis, and the use of radiotherapy and drugs to retard the growth and reproduction of the cells.

I. IA. SHAKHTMEISTER

melanoma

[mel·ə′nō·mə]
(medicine)
A malignant tumor composed of anaplastic melanocytes.
A benign or malignant tumor composed of melanocytes.

melanoma

Pathol a malignant tumour composed of melanocytes, occurring esp in the skin, often as a result of excessive exposure to sunlight
References in periodicals archive ?
Many patients with subungual melanoma have a history of a thin pigmented streak that had remained unchanged for years and then suddenly began to enlarge--eventually involving the entire nail bed with subsequent penetration to the eponychium or paronychium, ulceration, or granuloma formation.
Single streaks greater than 6 mm wide, those appearing in the sixth and seventh decade of life, streaks with a variegated color, or those that exhibit a broader proximal base or undergo any morphological change (indicating an active process) are suspicious for subungual melanoma.
Hutchinson's sign is pathognomonic for subungual melanoma only when accompanied by ulceration of the nail bed or obliteration of the nail plate by granuloma.
This makes the diagnosis of amelanotic subungual melanoma at best difficult, and often times impossible without a biopsy.
Subungual melanoma is quite rare in children of any race, though the incidence is not zero.
Once the diagnosis of subungual melanoma is confirmed the depth of invasion must be determined.
Amputation or wide excision are the only accepted treatments for subungual melanoma.
Subungual melanoma typically has a worse outcome than cutaneous melanoma, but the causes remain unclear.
Some recent studies have found that worse outcomes are tied to the fact that subungual melanoma often presents at a much more advanced stage than cutaneous melanoma, while other studies have shown that even when controlled for diseased and stage, subungual melanoma typically has a worse prognosis than cutaneous melanoma.
The early clinical signs of subungual melanoma are nail pigmentation, changes in nail contour, secondary infection, and ulceration of the nail bed
The ABC rule for clinical detection of subungual melanoma.
Amelanotic subungual melanoma mimicking pyogenic granuloma of the hand.