Melanoma (redirected from congenital melanoma of pigs)

melanoma: see skin cancer.

---

melanoma

Dark-coloured malignant tumour of skin cells that produce the protective skin-darkening pigment melanin. Melanomas are prone to metastasize (see cancer) and are associated with the highest death rate of any skin cancer. Removal, together with a collar of surrounding healthy skin, cures melanoma if done early. A common cause of melanoma is skin damage from sunlight. It is very rare in persons with dark skin.

---

melanoma

Pathol a malignant tumour composed of melanocytes, occurring esp in the skin, often as a result of excessive exposure to sunlight

---

melanoma [mel·ə′nō·mə]

(medicine)

A malignant tumor composed of anaplastic melanocytes.

A benign or malignant tumor composed of melanocytes.

---

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