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Related to amelanotic melanoma: Nodular 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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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.



A malignant tumor composed of anaplastic melanocytes.
A benign or malignant tumor composed of melanocytes.


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 ?
The framework then allowed the immunohistochemical diagnosis of metastatic amelanotic melanoma.
Development of cutaneus amelanotic melanoma in the absence of a functional tyrosinase.
Amelanotic melanoma may also be mistaken as a polyp if one is unaware of the entity.
An amelanotic melanoma appears similar to lymphoma, squamous cell carcinoma or other non-pigmented conditions, such as pyogenic granuloma, a conjunctival haematoma, a foreign body or argyrosis.
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.
In the case of amelanotic melanoma or large melanoma that has broken through BruclTs membrane, the double circulation sign is noted (Figure 6).
A case of a secondary amelanotic melanoma of the epiglottis was reported by Ikeda et al in 1991.
The remaining four lesions included one amelanotic melanoma and three with none or only one of the ABC criteria.
All clinically suspected pyogenic granulomas must be biopsied to rule out other conditions, such as irritational fibroma, hemangioma, Kaposi's sarcoma, leiomyoma, amelanotic melanoma, basal metastatic carcinoma, and squamous cell carcinoma.
Epithelioid sarcomas are sometimes composed of spindle-shaped cells, and they may be confused with other malignant spindle-cell neoplasms, such as synovial sarcomas, fibrosarcomas, angiosarcomas, malignant fibrous histiocytomas, malignant extrarenal rhabdoid tumor, epithelioid hemangioendothelioma, and amelanotic melanoma.
Depending on the patient's age and the location of the tumor, the differential diagnosis includes malignant schwannoma, malignant fibrous histiocytoma, fibrosarcoma, amelanotic melanoma, malignant lymphoma, squamous cell carcinoma, extramedullary plasmacytoma, metastatic tumor, glandular tumor, chondroma, chondrosarcoma, osteogenic sarcoma, and inverted papilloma.