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Related to melanoma: Nodular melanoma


a tumor arising from the melanocytic system of the skin and other organs. When used alone, the term refers to malignant melanoma.
acral-lentiginous melanoma an uncommon type of melanoma, although it is the most common type seen in nonwhite individuals, occurring chiefly on the palms and soles, and sometimes involving mucosal surfaces, such as the vulva or vagina. The characteristic lesion is an irregular, enlarging black macule, which has a prolonged noninvasive stage.
lenti´go malig´na melanoma a cutaneous malignant melanoma found most often on the sun-exposed areas of the skin, especially the face. It begins as a circumscribed macular patch of mottled pigmentation, showing shades of dark brown, tan, or black (lentigo maligna or melanotic freckle of Hutchinson), and enlarges by lateral growth before dermal invasion occurs. This type seems to be the least aggressive form of malignant melanoma.
malignant melanoma a malignant skin tumor, usually developing from a nevus and consisting of dark masses of cells with a marked tendency to metastasis. It is not common, but its incidence is increasing and it is the most aggressive type of skin cancer. It arises from pigment- (melanin-) producing cells and varies in course and prognosis according to type; types include superficial spreading melanoma, nodular malignant melanoma, and lentigo maligna melanoma. In general, the superficial lesions can be cured by surgical excision of the mole and adjacent tissues. Deeper lesions tend to metastasize rapidly through the lymphatic and circulatory systems. In some cases the condition has a genetic component. Early detection and skin protection are key in its control.


(mel'ă-nō'mă), Avoid the redundant phrase malignant melanoma.
A malignant neoplasm, derived from cells that are capable of forming melanin, arising most commonly in the skin of any part of the body, or in the eye, and, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites; occurs mostly in adults and may originate de novo or from a pigmented nevus or lentigo maligna. In the early phases, the cutaneous form is characterized by proliferation of cells at the dermal-epidermal junction, that soon invade adjacent tissues. The cells vary in amount and pigmentation of cytoplasm; the nuclei are relatively large and frequently bizarre in shape, with prominent acidophilic nucleoli; mitotic figures tend to be numerous. Prognosis correlates with the depth of skin invasion. Melanomas frequently metastasize widely; regional lymph nodes, skin, liver, lungs, and brain are likely to be involved. Intense, intermittent sun exposure, especially of fair-skinned children, increases the risk of melanoma later in life.
Synonym(s): malignant melanoma
[melano- + G. -ōma, tumor]


/mel·a·no·ma/ (mel″ah-no´mah) a tumor arising from the melanocytic system of the skin and other organs; used alone, it refers to malignant m..
acral-lentiginous melanoma  an irregular, enlarging black macule with a prolonged noninvasive stage, occurring chiefly on the palms and soles; it is the most common type of melanoma in nonwhite persons.
amelanotic melanoma  an unpigmented malignant melanoma.
lenti´go malig´na melanoma  a cutaneous malignant melanoma arising in the site of a preexisting lentigo maligna, occurring on sun exposed areas, particularly of the face.
malignant melanoma  a malignant tumor usually developing from a nevus or lentigo maligna and consisting of black masses of cells with a marked tendency to metastasis.
nodular melanoma  a type of malignant melanoma without a perceptible radial growth phase, usually occurring on the head, neck, or trunk as a uniformly pigmented, elevated, bizarrely colored, rapidly enlarging nodule that ulcerates.
ocular melanoma  malignant melanoma arising from the structures of the eye, frequently metastasizing and rapidly causing death.
subungual melanoma  acral-lentiginous melanoma in the nail fold or bed.
superficial spreading melanoma  malignant melanoma characterized by a period of radial growth atypical of epidermal melanocytes, which may be followed by invasive growth or may regress; it usually occurs as a small pigmented macule or papule with irregular outline on the lower leg or back.
uveal melanoma  ocular melanoma consisting of overgrowth of uveal melanocytes.


n. pl. melano·mas or melano·mata (-mə-tə)
A dark-pigmented, usually malignant tumor arising from a melanocyte and occurring most commonly in the skin.


[mel′ənō′mə] pl., melanomas, melanomata
Etymology: Gk, melas + oma, tumor
any of a group of malignant neoplasms that originate in the skin and that are composed of melanocytes. A melanocytic nevus may be acquired or congenital. The congenital melanocytic nevus is regarded as more likely to develop into a malignant melanoma, primarily because of its larger size. Smaller melanomas tend to develop from a pigmented nevus over several months or years. They may be sporadic and occur most commonly in fair-skinned people having light-colored eyes. A previous sunburn increases a person's risk. Any black or brown spot having an irregular border; pigment appearing to radiate beyond that border; a red, black, and blue coloration observable on close examination; or a nodular surface is suggestive of melanoma and is usually excised for biopsy. Melanomas are most commonly located on the upper back and lower legs of fair-skinned individuals and on the palms of the hands and insoles of the feet of dark-skinned individuals. Melanomas may metastasize and are among the most malignant of all skin cancers. Prognosis depends on the kind of melanoma; its size, depth of invasion, and location; and the age and condition of the patient. Because of the occurrence of melanomas and melanocytic nevi in certain families, a familial atypical mole and melanoma syndrome has been designated. It is defined by the occurrence of melanoma in one or more first- or second-degree relatives, a large number of moles, and moles that demonstrate certain cellular features. Patients with the syndrome have a high lifetime risk of development of melanoma. Kinds of melanoma are amelanic melanoma, benign juvenile melanoma, lentigo maligna melanoma, nodular melanoma, primary cutaneous melanoma, and superficial spreading melanoma. Compare blue nevus. See also Hutchinson's freckle.
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Malignant melanoma


A tumour that comprises 1–3% of all new cancers (18,000/year) and causes 6500 deaths/year (US), most age 30–50; melanoma is increasing at ± 7%/year, and now affects 9/105 (primarily the head and neck) in men and 12/105 (primarily legs) in women; it is rare but more aggressive in children.
Risk factors
Giant congential melanocytic nevus, dysplastic nevus, xeroderma pigmentosum, immunodeficiency, moles with persistent pigment changes (especially > age 15), large or irregularly pigmented lesions, familial moles, congenital moles, Caucasian (12-fold greater risk than Black), previous melanoma, melanoma in 1st-degree relative, immunosuppression, photosensitivity, increased sun exposure.
Site of metastasis
Liver, lung, intestine, pancreas, adrenal, heart, kidney, brain, spleen, thyroid.

Wide excision; chemo- and radiation are essentially useless.
Local recurrence common; many metastasise; 5-year survival reflects stage when diagnosed. 

Poor prognostic factors
Large size, paranasal/nasopharyngeal location, vascular invasion, high mitotic activity, marked cellular pleomorphism, distant metastases.

Stages of melanoma
▪ Stage I—Confined to epidermis and/or upper dermis, and measures ≤ 1.5-mm thick.
▪ Stage II—1.5-mm to 4-mm thick; spread to lower dermis but not beyond or to adjacent lymph nodes.
▪ Stage III—Any of the following:
   – > 4-mm thick;
   – Spread beyond the skin;
   – Satellite lesions within 2 cms of the original tumour; or
   – Spread to nearby lymph nodes or satellite lesions between original and regional lymph nodes.
▪ Stage IV—Metastases to other organs or to lymph nodes far from the original lesion.

Types of melanoma
Acral lentiginous melanoma
A rare, flat, palmoplantar or subungual lesion more common in non-whites; average 5-year survival < 50%; unrelated to actinic exposure, but possibly related to ectopic pigmentation.
Amelanotic melanoma
Rare, poorly differentiated, and occurs in those with a previous pigmented melanoma; since the Fontana-Masson stain is rarely positive in amelanotic melanoma, special studies are necessary, including immunoperoxidase staining with antibodies to the S-100 antigen and ultrastructural examination for presence of premelanosomes.
Lentigo maligna
Comprises 10% of melanomas; affects those > age 60; appears as flat, indolent lesions on face, arising from a premalignant freckle with greater than 90% 5-year survival; aetiologically linked to prolonged actinic exposure.
Nodular melanoma
15% of cases; similar clinically to superficial spreading melanoma; 50% average 5-year survival.
Premalignant melanoma
1/3 of lentigo maligna (Hutchinson’s freckle) progress to malignant melanoma after 10–15 years.
Superficial spreading melanoma
70% of cases; affects ages 30 to 60, especially female in lower legs or trunk, as a flat lesion (radial growth phase) that may be present for months to years; average 5-year survival 75%; aetiologically linked to recreational actinic exposure.
Thin melanoma (Stage-I cutaneous melanoma)
A lesion measuring < 1 cm in diameter; virtually 100% survival.


Malignant melanoma Dermatology A tumor which comprises 1-3% of all new cancers–18,000/yr, causes 6500 deaths/yr–US, most age 30–50; the incidence of melanoma is ↑ at ± 7%/yr, and now affects 9/105, primarily head & neck in ♂ and 12/105, primarily the legs in ♀; melanoma is rare, but more aggressive in chidren Risk factors Giant congential melanocytic nevus, dysplastic nevus, xeroderma pigmentosum, immunodeficiency, moles with persistent pigment changes–especially > age 15, large or irregularly pigmented lesions, familial moles, congenital moles; white–12-fold greater risk than blacks, previous melanoma, melanoma in 1st-degree relative, immunosuppression, photosensitivity, ↑ sun exposure; ocular melanomas may not ↑ melanoma risk Site of metastasis Liver, lung, intestine, pancreas, adrenal, heart, kidney, brain, spleen, thyroid. See Acral lentiginous melanoma, Amelanotic melanoma, Congenital melanoma, Dysplastic nevus syndrome, Lentigo maligna melanoma, Nodular melanoma, Ocular melanoma, Premalignant melanoma, Pseudomelanoma, Radial growth phase melanoma, Superficial spreading melanoma, Thin melanoma, Vertical growth phase melanoma, Vertical growth phase melanoma.
Stage I Confined to the epidermis and/or the upper dermis, and measures ≤ 1.5 mm thick
Stage II 1.5 mm to 4 mm thick, spread to lower dermis, but not beyond or to adjacent lymph nodes
Stage III Any of the following: (1) > 4 mm thick; (2) Spread beyond the skin; (3) Satellite lesions within 2 cms of the original tumor; or (4) Spread to nearby lymph nodes or satellite lesions between original and regional lymph nodes
Stage IV Metastases to other organs or to lymph nodes far from the original lesion


A malignant neoplasm, derived from cells that are capable of forming melanin, arising most commonly in the skin or in the eye, and, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites; occurs mostly in adults and may originate de novo or from a pigmented nevus or lentigo maligna. Melanomas frequently metastasize widely; regional lymph nodes, skin, liver, lungs, and brain are likely to be involved.


(mel?a-no'ma) [ melano- + -oma]
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A malignant tumor of darkly pigmented cells (melanocytes) that often arises in a brown or black mole. The tumor can spread aggressively throughout the body (e.g., to the brain and other internal organs). The incidence of the disease is rising rapidly in the US, esp. among people over 60. In 2008, the American Cancer Society estimated that 62,480 Americans would be diagnosed with melanoma and that more than 8,400 would die from the disease. More than 90% of melanomas develop on the skin; about 5% occur in the eye, and 2.5% occur on mucous membranes. See: illustration

The likelihood of long-term survival depends on the depth of the lesion (thicker lesions are more hazardous), whether it is ulcerated, the histological type (nodular and acral lentiginous melanomas are more dangerous than superficial spreading or lentigo malignant melanomas), the patient's age (older patients do more poorly), and gender (men tend to have a worse prognosis than women). See: ABCD; skin cancer


Excessive exposure to ultraviolet light, esp. sunlight, contributes to the development of melanoma, as does a family history of the disease. It is more common in fair-skinned than dark-skinned people and more common in people who have many moles on the skin than in those who have few. Total body skin examinations should be performed periodically on high-risk patients. On average, consistent screening identifies melanomas at an earlier stage (when they are thinner, or localized, rather than after they have spread) than those found on routine examination.


People spending considerable time outside should wear protective clothing to shield against ultraviolet radiation and use sunscreens (at least SPF15) on exposed skin.

Common melanoma sites are the back, shoulders, head and neck (men), the legs (women), and the backs. A skin biopsy and histologic examination can distinguish malignant melanoma from a benign nevus, seborrheic keratosis, or pigmented basal cell epithelioma; it also determines tumor thickness and tumor stage. Staging is based on the TNM system and Clark’s levels system, which classifies tumor progression according to skin layer penetration. Once diagnosed, patients need physical, psychological, and social assessment and care. Treatment options should be explained.


Melanomas are treated with surgery to remove the primary cancer and adjuvant therapies (chemotherapy and biotherapy) to reduce the risk of metastasis. Closure of a wide resection around an excised tumor may require skin grafting. Vaccines have been developed against melanoma; they appear to improve prognosis in affected patients.

Patient care

After surgery, dressings are inspected for drainage and signs of infection, and the patient is taught about prevention and signs to report. The patient should be taught that close follow-up care will be needed to detect recurrences at an early stage, and that this must continue for years (13% of recurrences develop more than 5 yrs after the primary lesion). When therapy fails, the patient and family will need referrals for palliative (hospice) care and may also require social services and spiritual care.

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desmoplastic melanoma

A rare type of malignant melanoma in which the typical melanotic pigmentation may be absent. It often occurs on the head or neck. Microscopically, the tumor cells are spindle-shaped. Local recurrences after surgical excision are common, as are metastases, esp. to the lungs.

in situ melanoma

A superficial melanoma that has not yet invaded deep layers of the skin or spread to local or distant tissues.


The lesion should be removed by an experienced surgeon.

Patient care

Patients diagnosed with melanoma in situ need careful follow-up examinations in case the tumor recurs, spreads, or is associated with other skin cancers.

small-diameter melanoma

A melanoma measuring less than 6 mm in diameter.


Any benign or malignant tumour of MELANOCYTES. See also MALIGNANT MELANOMA.


a highly malignant tumour of melanin-producing cells, usually occurring in the skin. Excessive exposure to UV radiation in strong sunlight is a contributory factor.


The most dangerous form of skin cancer. It should not be treated with cryotherapy, but should be removed surgically instead.
Mentioned in: Cryotherapy, Sunscreens


malignant neoplasm of melanocytes; capable of widespread metastasis (see Table 1)
  • cutaneous melanoma malignant epidermal tumour strongly associated (in fair-skinned or red-haired individuals) with prolonged childhood exposure to sunlight; a melanocytic naevus may undergo malignant change to form a melanoma; up to one-third of melanomas present as non-pigmented skin lesions (Table 2; see ABCDE; sign, Hutchinson's; Table 3 and Figure 1)

  • subungual melanoma melanotic or amelanotic malignant tumour arising from epidermal melanocytes within proximal nail fold

Table 1: Clinical features of presentations of malignant skin lesions
LesionClinical features
Lentigo malignant melanomaSlow-growing flat lesion, often affecting facial skin in the elderly
Irregular border, slowly extending
Variegated colour
May develop nodular centre, ulcerate and spread aggressively
Superficial spreading melanomaMay affect any skin area, especially in Caucasians (male back, female leg)
Irregular raised border, slowly extending
Central area may become pale and appear to 'resolve' (which designates that the lesion is invading underlying tissues)
Nodular melanomaMay affect any skin, but especially the lower limbs and trunk
Many lesions are amelanotic ± pigmented collar
Grows rapidly and bleeds easily
May be misdiagnosed as a vascular lesion
Acral lentiginous melanomaTends to present in black and oriental skin
Presents initially as a flat freckle-like lesion that extends and becomes nodular
Often underdiagnosed
Subungual melanomaMelanoma involving the nail unit
May be difficult to distinguish from benign melonychia or subungual haematoma
Tends to affect proximal nail area and eponychium, and spreads distally
Table 2: Clarke's levels, denoting the level of invasion of a skin tumour
ILesion confined to epidermis (i.e. in situ)
IIEpidermal lesion has just invaded into upper dermis
IIIEpidermal lesion has significantly invaded upper dermis
IVEpidermal lesion has invaded as far as deeper reticular dermis
VEpidermal lesion has invaded through dermis into subcuticular tissues

The greater the depth of lesion penetration, the more liable it is to undergo metastasis.

Table 3: Epidermal tumours that tend to malignancy
Seborrhoeic keratoses (senile or seborrhoeic wart; basal cell papilloma)Incidence increases with advancing age
Location: trunk, but also affect leg and foot
Aetiology: unknown
Cellular involvement: epidermal cells
Progression: start as small lesions which increase in size and degree of pigmentation over time
Edge: distinct edge which may overhang surrounding skin
Pigmentation: variable colour; homogeneous pigmentation
Surface: warty; horny cysts
Differential diagnosis: verrucae; hyperkeratosis
Treatment: liquid nitrogen; curettage
Bowen's disease (intraepidermal carcinoma in situ)Location: sun-exposed skin - face, neck, legs, dorsum of foot
Progression: slowly enlarging reddish, scaly patch; 1:20 lesions may progress to a squamous cell carcinoma
Cellular involvement: the entire epidermis is replaced by abnormal cells (atypical nuclei and mitosis patterns) but the basement membrane is normal
Edge: irregular, clearly demarcated margin
Surface: scaly or crusted
Differential diagnosis: psoriasis
Treatment: early stages: 5-fluorouracil; late stages: liquid nitrogen or curettage
Basal cell carcinoma (BCC) (rodent ulcer; basal cell epithelioma)Commonest skin tumour in Caucasians; incidence increases with advancing age; rarely metastatic
Location: sun-exposed skin: commonest on the face; rare on the foot
Progression: initially small lesion which gradually extends over months to years; it may crust over and appear to heal, but crust comes away to reveal the underlying lesion
Cellular involvement: basal-layer epidermal cells bud downwards toward the dermis to form dermal palisades
Edge: raised/rolled nodular (pearly) border
Surface: domed ± central eroding and extending ulcer
Differential diagnosis: Bowen's disease, squamous cell carcinoma, melanoma, vascular lesions
Treatment: excision and biopsy; liquid nitrogen, radiation therapy
Squamous cell carcinoma (SCC) (cutaneous cell carcinoma)Second most common cell tumour; locally destructive and may metastasize via the lymphatics
Aetiology: immune-suppressed patients; albinos; impaired DNA repair mechanisms; skin contaminants (soot, tar, mineral oils, hydrocarbons); as the end development of Bowen's disease or actinic keratoses; chronic irritation (such as in a long-standing leg ulcer); repeated exposure to radiation (ultraviolet, X-rays; radiant heat)
Location: any area of skin, but rare on the foot (a variant, verrucous carcinoma, is only found on the foot - see below)
Progression: begins as a reddish plaque mimicking dermatitis or eczema, becoming indurated
Edges: irregular and raised
Surface: nodular and/or irregular, ragged, sloughy, ulcer; oozing
Treatment: wide excision and biopsy; lymphadenectomy and radiation therapy if there is associated lymphatic spread
Verrucous carcinoma of the foot (epithelioma; carcinoma cingulatum)Location: at any skin site; predilection for plantar skin
Progression: initially resembles verruca plantaris; slowly progressive to form a nodular lesion and later a soggy, foul-smelling ulcer with sinuses somewhat remote from the main lesion
Cellular involvement: obviously malignant epidermal cells invade the dermis
Treatment: as for SCC
Figure 1: Bones of the foot. This article was published in Neale's Disorders of the Foot, Lorimer, French, O'Donnell, Burrow, Wall, Copyright Elsevier, (2006).


Tumour derived from cells that are capable of forming melanin.
choroidal melanoma The most common primary malignant tumour in the eye in adults. It appears under ophthalmoscopic examination as a pigmented, elevated mass, usually brown in colour and sometimes with orange pigment (lipofuscin). The tumour may cause a decrease in vision or brief 'balls of light' moving cross the visual field, or be asymptomatic, depending on its size or location. The condition is typically unilateral. Differential diagnosis with retinal detachment or choroidal naevus is essential. Treatment may include radiotherapy or photocoagulation, or enucleation if the melanoma is large and vision irreversibly lost. Syn. malignant melanoma of the choroid.
iris melanoma A pigmented lesion, which is easily seen on the surface of the iris. It alters the colour of the iris and may distort the shape of the pupil. A dilated episcleral vessel running towards the tumour may be present. There may be a localized cataract where the tumour is in contact with the lens and secondary glaucoma may develop if the tumour has spread to the angle of the anterior chamber. The tumour arises from the iris stroma and is composed of epitheloid or spindle cells, or a mixture of both. It is almost always unilateral and most commonly found in white patients with light irides. It is thought to originate from a previous pigmented naevus. If the tumour is found to enlarge it will usually be excised surgically. (Fig. M7) See iris naevus.
uveal melanoma Tumour which may be located in the choroid, the ciliary body or the iris. Choroidal melanomas make up about 85% of the total, ciliary body about 10% and iris about 5%. Although uveal melanomas can occur at any age, the majority of patients are beyond the age of 40 years. Uveal melanomas can metastasize, especially choroidal melanomas. Diagnosis is best achieved with a B-scan ultrasound examination. The patient must be referred to an ocular oncologist without delay. See ultrasonography.
Fig. M7 Iris melanoma of the left eyeenlarge picture
Fig. M7 Iris melanoma of the left eye


Malignant neoplasm, derived from cells capable of forming melanin, arising in skin of any part of the body, or in the eye, and, rarely, in mucous membranes of the genitalia, anus, oral cavity, or other sites.

melanoma (mel´ənō´mə),

n a malignant epithelial neoplasm characterized by pigment-producing cells. It usually is dark in color but may be amelanotic, i.e., free of pigment. It can occur in skin as well as the oral cavity, where it usually would be a late finding. It can occur at the site of a mole (mainly) or another site.


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 ?
Since 1982, the rate of melanoma in the population has almost doubled-up from 27 to 49 cases per 100,000 people,' said AIHW spokesperson Justin Harvey.
Mucosal melanoma usually presents after the 6th decade.
The report analyzes treatment usage patterns, drug types available and pipeline and market forecasts across indications for melanoma.
Unlike other cancers, melanoma can be diagnosed by getting a skin check.
The newest melanoma staging system from the recently published seventh edition of the AJCC Cancer Staging Manual has been in use since 2010 (7), (8).
Shore said that he believes the total absence of nodular melanoma for the first 17 years of his program is best explained by the program's detection of previously unrecognized early melanomas that he suspects have the potential to become nodular lesions.
Two features which lead to suspicion of subungual melanoma are the associated pigmentation of the adjacent nail fold (Hutchinson's sign) and progressive elevation of the nail from the nail bed.
Two important strategies can help minimize missing melanoma, he said.
Melanoma risk is 30-70 times higher in individuals with a significant family history compared with the general population.
Cancer patients whose cells showed more chromosome breaks after UVB irradiation were 3 times more likely than the general population to have BCC or SCC, but were not more likely to have melanoma.
Lipstone, 45, recalls when Mark Winkler, her friend since childhood, was diagnosed with melanoma, the deadliest form of skin cancer.

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