Lentigo | DermNet New Zealand DermNet New Zealand Author: Vanessa Ngan, Staff Writer, 2006. Updated by A/Prof Amanda Oakley, February 2016. What is a lentigo? A lentigo is a pigmented flat or slightly raised lesion with a clearly defined edge. Unlike an ephilis (freckle), it does not fade in the winter months. There are several kinds of lentigo. The name lentigo originally referred to its appearance resembling a small lentil. The plural of lentigo is lentigines, although “lentigos” is also in common use. Who gets lentigines? Lentigines can affect males and females of all ages and races. Solar lentigines are especially prevalent in fair skinned adults. Lentigines associated with syndromes are present at birth or arise during childhood. What causes lentigines? Common forms of lentigo are due to exposure to ultraviolet radiation: Sun damage including sunburn Phototherapy , especially photochemotherapy ( PUVA ) Ionising radiation, eg radiation therapy , can also cause lentigines.

Several familial syndromes associated with widespread lentigines originate from mutations in Ras-MAP kinase, mTOR signalling and PTEN pathways. What are the clinical features of lentigines? Lentigines have been classified into several different types depending on what they look like, where they appear on the body, causative factors, and whether they are associated to other diseases or conditions. Lentigines may be solitary or more often, multiple. Most lentigines are smaller than 5 mm in diameter.

Lentigo simplex A precursor to junctional naevus Arises during childhood and early adult life Found on trunk and limbs Small brown round or oval macule or thin plaque Jagged or smooth edge May have a dry surface May disappear in time A precursor to seborrhoeic keratosis Found on chronically sun exposed sites such as hands, face, lower legs May also follow sunburn to shoulders Yellow, light or dark brown regular or irregular macule or thin plaque May have a dry surface Often has moth-eaten outline Can slowly enlarge to several centimetres in diameter May disappear, often through the process known as lichenoid keratosis Solar lentigo Also known as reticulated lentigo Few in number compared to solar lentigines Follows sunburn in very fair skinned individuals Dark brown to black irregular ink spot-like macule Ink spot lentigo Similar to ink spot lentigo but follows photochemotherapy (PUVA) Location anywhere exposed to PUVA PUVA lentigo Similar to ink spot lentigo but follows indoor tanning Location anywhere exposed to tanning bed Tanning bed lentigo Lentigo Clinical Presentation: History, Physical, Causes Lentigo Clinical Presentation Author: Robert A Schwartz, MD, MPH; Chief Editor: William D James, MD

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Share The initial appearance of lentigines varies widely and depends on the following: Race Other factors, depending on the type of lentigo Next: The physical appearance and morphology of lentigines depend on the type of lesion. Lentigo simplex Lentigo simplex (eg, simple lentigo, juvenile lentigo) is the most common form of lentigo. Lentigo simplex is not induced by sun exposure, and it is not associated with systemic disease. Clinically, the lesions are round or oval asymptomatic macules that are 3-15 mm in diameter. Their margins can be either jagged or smooth. Pigmentation is evenly distributed, with a color ranging from brown to black. The lesions are few in number and may occur anywhere on the skin or mucous membranes. The lesions usually appear first in early childhood, but they can also be present at birth or develop later. Multiple dysplastic nevi and lentigines were reduced in number in a patient with familial gastrointestinal stromal tumors syndrome after treatment with imatinib mesylate. [ 13 ] The effect of effect of imatinib on pigmentation is not well understood.

Solar lentigo Solar lentigo (eg, actinic lentigo, senile lentigo, sun spot, liver spot) is the most common benign sun-induced lesion that occurs in sun-exposed areas. Solar lentigo most commonly appears on the face, arms, dorsa of the hands, and upper part of the trunk. The spots initially are smaller than 5 mm in diameter. The surface of the lesions is either flat or depressed, and it may be split by fine wrinkles. The lesions are usually brown, but the color may range from yellow-tan to black. Older lesions are often dark brown or brownish black. Solar lentigines slowly increase in number and in size. Many lesions eventually coalesce to form larger patches. Although these lesions are most common in individuals aged 30-50 years, they are now seen in younger individuals because of their increased exposure to sun tanning and the use of artificial sources of UV light. Although they are often called liver spots, they are not a manifestation of systemic disease. In vivo reflectance confocal microscopy may show solar lentigines having increased melanin and hemoglobin levels and a higher rate of epidermal proliferation.

Deformation and the number of the hyperrefractive dermal papillary rings may increase significantly over the 5-year time span, with the lentigo size enhanced and color darkened. [ 14 ] Ink-spot lentigo Ink-spot lentigo (ie, reticulated black solar lentigo) can be distinguished by a wiry or beaded, markedly irregular outline; these lesions occur in patients of Celtic ancestry. The benign lesions have a reticulated pattern, and most lesions resemble a spot of ink. The distribution is limited to sun-exposed areas of the body, similar to that of solar lentigo; however, in contrast to solar lentigines, patients usually have only 1 ink-spot lentigo. The most common presentation includes 1 ink-spot lentigo among an extensive number of solar lentigines. These lesions can also be distinguished from the darkly pigmented PUVA lentigo by their more reticulated or beaded pattern and multiple central and peripheral skip areas. Ink-spot lentigines can initially suggest melanoma because of their dark color, irregular border, and limited number; however, further investigation, which may include biopsy, reveals the characteristic features of these benign lesions.

PUVA lentigo PUVA lentigo is a persistent, pale brown macule appearing 6 months or longer after the start of PUVA therapy for psoriasis. The lesions resemble solar lentigines, but they often have more irregular borders and may mimic ephelides. The occurrence of lesions is closely associated with greater cumulative doses of PUVA, and the lesions may occur on all treatment sites. The most common areas include the upper part of the chest and back, groin, buttocks, glans penis, and penile shaft. The axillae, palms, soles, and gluteal cleft are spared. The lesions vary from 3-8 mm in diameter, but stellate lesions can be as large as 3 cm in diameter. The lentigines may persist for 3-6 months after therapy is discontinued. In contrast, stellate lesions can persist longer than 2 years. Radiation lentigo Radiation lentigo resembles UV-induced lentigo, but it often includes other histopathologic signs of long-term cutaneous radiation damage such as epidermal atrophy, subcutaneous fibrosis, keratosis, and telangiectasias.

The presence of a radiation lentigo is considered an indicator of a prior cutaneous exposure to a large single dose of ionizing radiation (eg, exposure during the Chernobyl nuclear accident). These lesions have not been shown to occur after local fractionated radiation therapy. Radiation lentigines are persistent and typically occur 4 months or longer after the initial exposure. The malignant potential of the lesions is unknown; however, the induction of melanoma by ionizing radiation has never been proven. Tanning-bed lentigines Tanning-bed lentigines [ 15 , 16 , 17 ] usually occur in women with a history of tanning-bed use. Tanning-bed lentigines are similar to PUVA lentigines, except psoralens are not involved. The site of tanning-bed lentigines is primarily acral despite whole-body exposure. The most common areas include the anterior aspects of the arms and legs, but they can also occur on the neck and chest. The size of the lesions varies. The lesions are usually 2-5 mm in diameter, with color ranging from dark brown to black. Some lentigines may coalesce and enlarge.

Pigmentation of the lesions may be uneven, with irregular or stellate shapes. The lesions can appear abruptly after intense tanning, or they can appear after prolonged (eg, 1 y) regular use of tanning beds. The malignant potential of the lesions is unknown. Oral and labial melanotic macules Oral and labial melanotic macules are similar to each other. Labial lesions almost always occur on the vermilion of the lower lip, and their color ranges from brown to blue to blue-black. Occasionally, variegated pigmentation occurs. The lesions are usually solitary, symmetric, and asymptomatic. Oral lesions can appear on the gingiva, buccal mucosa, palate, and tongue. Usually, oral and labial lesions have a diameter smaller than 4 mm. The individual's age at onset ranges from 25-71 years. The differential diagnosis should include Laugier-Hunziker syndrome and Peutz-Jeghers syndrome . The absence of systemic features and involvement at other sites should assist in differentiating oral and labial melanotic macules from these syndromes.

Both oral and labial melanotic macules are benign; however, lesions suggestive of malignancy should be examined at biopsy. Vulvar and penile lentigo Vulvar and penile lentigo are benign lesions similar to labial melanotic macules. In men, the most common sites are the glans penis, corona, corona sulcus, and penile shaft. The lesions vary in color from tan to brown to dark brown, and they have irregular borders and skip areas. Individual lesions may have a diameter as large as 15 mm. In women, the lesions appear anywhere on the genital mucosa as a mottled, pigmented patch with skip areas. The diameter can be 5-15 mm or larger. The lesions may also occur in episiotomy scars after childbirth. Lentigines involving the external genitalia are also reported in LAMB syndrome. Lentigines profusa Lentigines profusa (ie, generalized lentigines) is characterized by numerous lentigines without signs of associated abnormalities or triggering factors. The clinical appearance of lentigines profusa resembles that of ephelides, but its distribution is widespread.

Usual areas of involvement include the extremities, trunk, palms, and genitalia. Mucosal surfaces such as the conjunctiva can also be affected, but the buccal mucosa may be spared. The macules vary from 1 mm to 2 cm in diameter. The color of the macules ranges from dark brown to black. Lentigines profusa appears similar to the cutaneous manifestations of LEOPARD, LAMB, and NAME syndromes; however, a notable exception is the absence of the variety of the physical anomalies and defects associated with these syndromes. Agminated lentiginosis Agminated (segmental, unilateral, partial unilateral) lentiginosis is characterized by numerous lentigines confined to a body segment, with a sharp demarcation at the midline. The distribution frequently corresponds to one or more dermatomes. Less commonly, the lesions can be distributed unilaterally, bilaterally, in a checkerboard pattern, or in midline clusters. Usually, the disease appears in early childhood, although the lentigines may also be noted at birth. These lesions have been associated with numerous diseases.

Clinically, the lesions appear as circumscribed, tan or dark brown macules on healthy background skin. Xeroderma pigmentosum Xeroderma pigmentosum (XP) is an autosomal-recessive condition involving abnormalities that stem from an inability of cells to repair DNA damage induced by exposure to UV light and certain chemicals. Clinically, patients have skin atrophy and progressive pigmentary changes. Subsequently, neoplastic changes occur on the skin, often in childhood; squamous cell and basal cell carcinomas are the most common malignancies. Other cancers, such as melanoma, may appear as well. All of these neoplastic changes evolve on sun-exposed areas, particularly the head, neck, and face. XP is diagnosed in young children, who are typically healthy. Children should avoid sun exposure because the acceleration of skin changes leads to the formation of neoplasms. Ocular and neurologic defects are also associated with XP. See the image below. Thirteen-year-old Greek adolescent with xeroderma pigmentosum.

View Media Gallery LEOPARD syndrome LEOPARD syndrome (lentigines, electrocardiographic conduction defects, ocular hypertelorism, pulmonary stenosis, abnormal genitalia, retardation of growth, and deafness syndrome) (ie, multiple lentigines syndrome) is a complex dysmorphogenetic disorder that is transmitted as an autosomal-dominant trait with variable penetrance. A mutation of the PTPN11 gene may be documented. [ 18 ] The diagnosis can be difficult because most patients have only 3-5 of the criteria. Lentigines are the most common feature of the syndrome, although they do not have to be present to diagnose LEOPARD syndrome. In the absence of lentigines, the diagnosis can be made if the patient has 3 features of the disease and an immediate relative with the disease. Lentigines are present at birth and increase in number until puberty. The intensity of the pigmentation varies. The lesions are numerous on the neck and trunk, but they can also be widespread and involve the genitalia, palms, soles, and scalp. Lentigines spare some parts of the face and may be limited to one side of the body in some cases.

Peutz-Jeghers syndrome Peutz-Jeghers syndrome is an autosomal-dominant condition with a high degree of penetrance and is characterized by gastrointestinal polyps and pigmented macules. The polyps are benign hamartomas that can affect the entire bowel, most characteristically the jejunum. These polyps result in recurrent perirectal bleeding and abdominal pain. Patients are often first seen with bleeding or with intussusception that manifests as an obstruction, abdominal pain, rectal prolapse, vomiting, and/or currant jelly–like stool. Lentigines are brown-to-black-to-blue macules that usually arise in early childhood. Their size ranges from 1-12 mm in diameter. Hyperpigmented macules occur in more than 95% of patients, and they have a characteristic distribution around the mouth, on the lips, and on the buccal mucous membranes; they can also be scattered around the nose and face. Additionally, lesions appear on the fingers and toes on both the palmar and volar surfaces. Lesions are characteristically absent on the flexor and extensor surfaces of the rest of the body.

The buccal mucosal macules are important because they persist, whereas the other macules may fade with age. A relationship between the extent of melanosis and the extent of polyposis has not been found. Almost all women have unusual sex cord tumors that are small, bilateral, asymptomatic, and multifocal. Gonadal tumors are also noted in men. Women have an increased risk of breast cancer, either unilateral or bilateral in presentation. Laugier-Hunziker syndrome Laugier-Hunziker syndrome is characterized by a variable number of pigmented macules that most commonly appear on the lower lip; buccal mucosa; hard palate; and, occasionally, tips of the fingers. Other locations include the labial commissure, tongue, gums, floor of the mouth, neck, thorax, abdomen, nails, and soles. The lentigines may be numerous and confluent, but they rarely occur in a linear pattern. The lesions mostly occur on the nails. Their borders are smooth and well defined. The color of the lesions can vary from gray to brown, blue, or black. Although the syndrome has a chronic course without remission, individuals are generally asymptomatic.

This syndrome differs from Peutz-Jeghers syndrome because of the absence of intestinal polyps. Laugier-Hunziker syndrome occurs in individuals aged 20-50 years and in both sexes, whereas isolated labial melanotic macules affect younger patients and are usually solitary. Pigmentation of the oral mucosa and nails is reported to occur in patients taking the antiretroviral medication zidovudine. The clinical and drug histories are important in differentiating this phenomenon from Laugier-Hunziker disease. Myxoma syndrome The myxoma syndrome is associated with mucocutaneous lentigines along with various additional abnormalities. Some constellations of abnormalities have been given specific names. They may all be part of a spectrum of manifestations of the same disorder. LAMB syndrome LAMB (lentigines, atrial myxomas, mucocutaneous myxomas, and blue nevi) syndrome is one of the myxoma syndromes. The lentigines most commonly occur on the lips, face, sclera, and vulva. The lesions are brown and can be as large as 1 cm in diameter.

The mucocutaneous myxomas appear as papules or dermal nodules at various sites on the body, including the breasts, shoulders, oral mucosa, and tongue. Cardiac myxomas are rare in children and usually occur in the form of atrial myxomas, which are clinically evident as intermittent embolic episodes and valvular obstructions. An association with benign thyroid nodules is noted. NAME syndrome NAME (nevi, atrial myxoma, myxoid neurofibroma, and ephelides) syndrome is another myxoma syndrome. This possible variant of LAMB syndrome involves multiple, flat, pigmented macules. The lesions begin at birth and are accentuated in the summer. The color of the lesions varies from pale to dark brown. The most commonly involved areas are the neck, trunk, and thighs. The palms and soles are sometimes affected. Carney syndrome Carney syndrome is an autosomal dominant multiple neoplasia syndrome involving cardiac, cutaneous, and mammary myxomatous masses; lentigines; blue nevi; endocrine disorders; and testicular tumors. [ 19 ] Often, multicentric and bilateral organ involvement is present; this usually occurs in young patients.

The cutaneous myxomas are often observed on the eyelids and other sites such as the nipples, scalp, face, oral mucosa, ears, neck, trunk, limbs, and perineum. Cardiac myxomas are either single or multiple and often result in fibrosis or calcification. Two types of pigmented macules exist: blue nevi and lentigines. Lentigines are brown to black and 0.2-2 mm in diameter; they have irregularly shaped, jagged margins. They are widespread throughout the body and may coalesce to form brown patches. The lesions can be found on the face, eyelids, ears, vermilion borders of the lips, conjunctiva, vulva, extremities, and glans penis. Unlike Peutz-Jeghers syndrome, Carney syndrome infrequently involves buccal lesions. Endocrine involvement includes calcifying pigmented neuroectodermal tumors, pituitary adenomas with acromegaly and gigantism, and adrenocortical disease leading to Cushing syndrome. Testicular tumors feature Sertoli cell tumors, Leydig cell tumors, and adrenocortical rest tumors.

Mammary involvement includes gynecomastia and myxomatous enlargement of the stroma. Inherited patterned lentiginosis Inherited patterned lentiginosis can occur in blacks. This form is characterized by hyperpigmented macules on the face and lips. At times, additional lesions are seen on the elbows, knees, buttocks, and palmoplantar surfaces. Lesions are not present on the oral mucosa, and they are not associated with organ involvement or an apparent risk of cancer. The inheritance pattern appears to be autosomal dominant. Light-skinned African American families, some of whom have a mixed American Indian heritage and those with relatives with red hair, are particularly affected. See the image below. Ephelides (ie, freckles) on the forearm of a 26-year-old redheaded patient. View Media Gallery Nevus spilus The nevus spilus is a both a lentigo and melanocytic nevus, a unique neoplasm that has only a slight potential to develop into melanoma. [ 20 ] It is evident as multiple pigmented macules or papules within a congenital or acquired pigmented patch.

Previous Skin Conditions: Moles, Skin Tags & More | Cleveland Clinic There are several skin lesions that are very common and almost always benign (non-cancerous). These conditions include moles , freckles, skin tags, benign lentigines, and seborrheic keratoses. What is a mole? Moles are growths on the skin that are usually brown or black. Moles can appear anywhere on the skin, alone or in groups. Most moles appear in early childhood and during the first 20 years of a person's life. Some moles might not appear until later in life. It is normal to have between 10 to 40 moles by adulthood. As the years pass, moles usually change slowly, becoming raised and lighter in color. Often, hairs develop on the mole. Some moles will not change at all, while others will slowly disappear over time. What causes a mole? Moles occur when cells in the skin grow in a cluster instead of being spread throughout the skin. These cells are called melanocytes, and they make the pigment that gives skin its natural color. Moles might darken after exposure to the sun, during the teen years, and during pregnancy .

What should I look for when examining my moles? Most moles are benign. The only moles that are of medical concern are those that look different than other existing moles or those that first appear after age 20. If you notice changes in a mole's color, height, size, or shape, you should have a dermatologist (skin doctor) evaluate it. You also should have moles checked if they bleed, ooze, itch, appear scaly, or become tender or painful. Examine your skin with a mirror or ask someone to help you. Pay special attention to areas of your skin that are often exposed to the sun, such as the hands, arms, chest, neck, face, and ears. If your moles do not change over time, there is little reason for concern. If you see any signs of change in an existing mole, if you have a new mole, or if you want a mole to be removed for cosmetic reasons, talk to your dermatologist. The following ABCDEs are important signs of moles that could be cancerous.

If a mole displays any of the signs listed below, have it checked immediately by a dermatologist: Asymmetry: One half of the mole does not match the other half. Border: The border or edges of the mole are ragged, blurred, or irregular. Color: The color of the mole is not the same throughout or has shades of tan, brown, black, blue, white, or red. Diameter: The diameter of a mole is larger than the eraser of a pencil. Elevation/Evolution: A mole appears elevated, or raised from the skin. Are the moles changing over time? Melanoma is a form of skin cancer. The most common location for melanoma in men is the back; in women, it is the lower leg. Melanoma is the most common cancer in women ages 25 to 29. What are the different types of moles? Congenital nevi are moles that appear at birth. Congenital nevi occur in about one in 100 people. These moles might be more likely to develop into melanoma than are moles that appear after birth. If the mole is more than eight inches in diameter, it poses more risk of becoming cancerous.

Dysplastic nevi are moles that are larger than average (larger than a pencil eraser) and irregular in shape. They tend to have uneven color with dark brown centers and lighter, uneven edges. These moles tend to be hereditary. People with dysplastic nevi might have more than 100 moles and have a greater chance of developing malignant (cancerous) melanoma. Any changes in the mole should be checked by a dermatologist to detect skin cancer. How are moles treated? If a dermatologist believes the mole needs to be evaluated further or removed entirely, he or she will first take a biopsy (small tissue sample of the mole) to examine thin sections of the tissue under a microscope. This is a simple procedure. (If the dermatologist thinks the mole might be cancerous, cutting through the mole will not cause the cancer to spread.) If the mole is found to be cancerous, the dermatologist will remove the entire mole by cutting out the entire mole and a rim of normal skin around it, and stitching the wound closed. What is a skin tag? A skin tag is a small flap of tissue that hangs off the skin by a connecting stalk. Skin tags are benign and are not dangerous.

They are usually found on the neck, chest, back, armpits, under the breasts, or in the groin area. Skin tags appear most often in women, especially with weight gain, and in middle-aged and elderly people. Skin tags usually don’t cause any pain. However, they can become irritated if anything such as clothing or jewelry rubs on them. How are skin tags treated? Your dermatologist can remove a skin tag by cutting it off with a scalpel or scissors, with cryotherapy (freezing it off), or with electrosurgery (burning with an electric current). What is a lentigo? A lentigo (plural: lentigines) is a spot on the skin that is darker (usually brown) than the surrounding skin. Lentigines are more common among Caucasian patients, especially those with fair skin, but can occur in anyone. What are the causes of lentigines? Exposure to the sun seems to be the major cause of lentigines. Lentigines most often appear on parts of the body that get the most sun, including the face and hands. Some lentigines might be caused by genetics (family history) or by medical procedures such as radiation therapy . How are lentigines treated?

There are several methods for treating lentigines: Cryotherapy (freezing it off) Creams that are applied to the skin (These include retinoids and bleaching agents.) Can lentigines be prevented? The best way to prevent lentigines is to stay out of the sun as much as possible. Use sunscreen when outdoors, and avoid using a tanning bed to get a suntan. What are freckles? Freckles are small brown spots usually found on the face and arms. Freckles are extremely common and are not a health threat. They are more often seen in the summer, especially among lighter-skinned people and people with light or red hair. However, freckles can occur in anyone, and appear as darker brown spots in people with darker skin. Both men and women get freckles at an equal rate. What causes freckles? Causes of freckles include genetics, diseases (such as xeroderma pigmentosum, a rare disease that causes an increased sensitivity to ultraviolet light, such as the sun), and exposure to the sun. What is the treatment for freckles? Since freckles are almost always harmless, there really is no need to treat them.

As with many skin conditions, it’s best to avoid the sun as much as possible, or use a sunscreen. This is especially important because people who freckle easily (such as lighter-skinned people) are more likely to develop skin cancer. If you feel that your freckles are a problem or you don’t like the way they look, you can cover them up with makeup. What are seborrheic keratoses? Seborrheic keratoses are brown or black growths usually found on the chest and back, as well as on the head. They originate from cells called keratinocytes. As they develop, seborrheic keratoses take on a warty appearance. What causes seborrheic keratoses? The cause of seborrheic keratoses is unknown. They are seen more often as people get older. They do not lead to skin cancer. How are seborrheic keratoses treated? Seborrheic keratoses are benign and are not contagious. Therefore, they don’t need to be treated.

If you decide to have seborrheic keratoses removed because you don’t like the way they look, or because they are chronically irritated by clothing, methods for removing them include cutting them off, cryotherapy, and electrosurgery. Can seborrheic keratoses be prevented? Seborrheic keratoses can’t be prevented. References: National Institute on Aging. AgePage: skin care and aging . Accessed 2/24/2016. Woodhouse JG, Tomecki KJ. Common benign growths. In: Carey WD, ed. Cleveland Clinic: Current Clinical Medicine 2010. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2010:section 3. © Copyright 1995-2016 The Cleveland Clinic Foundation. All rights reserved. This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition.

This document was last reviewed on: 5/23/2014...#12014 Lentigo maligna and lentigo maligna melanoma | DermNet New Zealand Home » Topics A–Z » Lentigo maligna and lentigo maligna melanoma Lentigo maligna and lentigo maligna melanoma Author: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton New Zealand, 2011. Lentigo maligna is a precursor to lentigo maligna melanoma, a potentially serious form of skin cancer . Lentigo maligna is also known as Hutchinson melanotic freckle. According to New Zealand Cancer Registry data, 2256 invasive melanomas were diagnosed in 2008 and about 10% were pathologically lentigo maligna melanoma. Rates of the precursor, lentigo maligna, are not reported by national cancer registries but it is thought to be the most common variant of melanoma in situ in New Zealand and Australia. What is lentigo maligna?

Lentigo maligna is an early form of melanoma in which the malignant cells are confined to the tissue of origin, the epidermis, hence it is often reported as ‘in situ’ melanoma. It occurs in sun damaged skin so is generally found on the face or neck, particularly the nose and cheek. It grows slowly in diameter over 5 to 20 years or longer. Lentigo maligna melanoma is diagnosed when the malignant melanoma cells have invaded into the dermis and deeper layers of skin. Lentigo maligna has a lower rate of transformation to invasive melanoma than the other forms of melanoma in situ (under 5% overall). However, the risk of invasive melanoma is greater in larger lesions, with up to 50% of those with diameter of greater than 4 cm being reported to have an invasive focus. Who gets lentigo maligna? The risk of lentigo maligna relates to sun damage. Thus lentigo maligna is more common in outdoor workers, in older people and in association with solar damage and keratinocyte skin cancer ( basal cell carcinoma , squamous cell carcinoma ).

Although often occurring in those with very fair skin ( skin phototype 1 and 2), it may also occur in those who tan quite easily (phototype 3). It is rare in brown or black skin (phototype 4-6). Lentigo maligna is more common in males than females. The majority of patients with lentigo maligna are older than 40 years, and the peak age of diagnosis is be between 60 and 80 years. Unlike superficial spreading melanoma , lentigo maligna is not related to the number of melanocytic naevi ( moles ) or atypical naevi . What does lentigo maligna look like? Lentigo maligna presents as a slowly growing or changing patch of discoloured skin. At first, it often resembles common freckles or brown marks ( lentigines ). It becomes more distinctive in time, often growing to several centimetres over several years or even decades. Like other flat forms of melanoma, it can be recognised by the ABCDE rule: Asymmetry, Border irregularity, Colour variation, large Diameter and Evolving.

The characteristics of lentigo maligna include: Large size: >6 mm and often several centimetres in diameter at diagnosis Irregular shape Variable pigmentation – colours may include light brown or tan, dark brown, pink, red or white Smooth surface. Lentigo maligna Invasive melanoma is reported to arise within lentigo maligna in 3-10% of cases. It may be difficult to determine whether this has occurred just from the appearance, but the following features are very suspicious. Thickening of part of the lesion Increasing number of colours, especially blue or black Ulceration or bleeding More images of lentigo maligna melanoma ... What is the cause of lentigo maligna? Lentigo maligna is a proliferation of malignant pigment cells (melanocytes) along the basal layer of the epidermis and within the hair follicle. What triggers the cells to become malignant is unknown but genetic mutations may start within primitive stem cells. Solar damage results in a degree of immune tolerance, allowing abnormal cells to grow unchecked. What tests should be done if I have lentigo maligna? It is essential to diagnose lentigo maligna and lentigo maligna melanoma accurately.

Clinical diagnosis is aided by dermoscopy and in some centres, by confocal microscopy . New techniques are being evaluated to help identify the margin of lentigo maligna prior to excision biopsy. Other tests are not necessary in the majority of patients but those with invasive melanoma that is more than 1 mm thick may be advised to have imaging studies, lymph node biopsy and blood tests. New tests are being developed to determine specific genetic mutations with lentigo maligna melanoma, which may inform future targeted therapy. Dermoscopy of lentigo maligna Dermoscopy (also called dermatoscopy), or the use of a dermatoscope, by a dermatologist or other doctor trained in its use, can be very helpful in distinguishing lentigo maligna from other types of skin lesion. However, the dermoscopic appearance of early lentigo maligna can be difficult to distinguish from other pigmented lesions, particularly on the face. Seborrhoeic keratoses Facial pigmented lesions are characterised dermoscopically by pseudonetwork – this is pigmentation arising around prominent facial hair follicles, and several types of skin lesion may appear rather similar to lentigo maligna.

However, lentigo maligna shows greater variation in the thickness of the lines making up the network, often forming an atypical rhomboid pattern associated with greyish dots, the structure tends to be irregular, and there is variation in colour. Diagnostic excision biopsy of lesion suspicious of melanoma If a skin lesion is clinically suspicious of lentigo maligna, it is best cut out ( excision biopsy ) with a 2-3 mm margin. Partial biopsy is less accurate than complete excision biopsy, as a single small biopsy could miss a malignant focus. However sometimes the lesion is very large, and before performing significant surgery, a partial biopsy is arranged to confirm the diagnosis. The doctor should remove a long ellipse of skin, take biopsies from multiple sites or carefully shave a representative area for histology. The pathological diagnosis of melanoma and its precursors can be very difficult. Some lesions clinically typical of lentigo maligna are reported to show junctional melanocytic proliferation alone, others have the criteria to diagnose in situ melanoma, and a few show invasive cancer. The histological features of lentigo maligna include a predominantly junctional confluent proliferation of melanocytes and extension along adnexal structures.

Solar elastosis (degeneration of elastic tissue within dermis) is typically prominent. Immunostains eg SAC R21 may improve accuracy of diagnosis in borderline cases. Pathology report in melanoma The pathologist's report should include a macroscopic description of the specimen and melanoma (the naked eye view), and a microscopic description. The following features should be reported if there is invasive melanoma. Diagnosis of primary melanoma Margins of excision i.e. the normal tissue around the tumour Mitotic rate – a measure of how fast the cells are proliferating Whether or not there is ulceration The report may also include comments about the cell type and its growth pattern, invasion of blood vessels or nerves, inflammatory response, regression and whether there is associated in-situ disease. What is Breslow thickness? The Breslow thickness is reported for invasive melanomas. It is measured vertically in millimetres from the top of the granular layer (or base of superficial ulceration) to the deepest point of tumour involvement. It is a strong predictor of outcome; the thicker the melanoma, the more likely it is to metastasise (spread). What is the Clark level of invasion?

The Clark level indicates the anatomic plane of invasion. Level Melanoma has invaded reticular dermis Level 5 Melanoma has invaded subcutaneous tissue The deeper the Clark level, the greater the risk of metastasis (secondary spread). It is useful in predicting outcome in thin tumours, and less useful for thicker ones in comparison to the value of the Breslow thickness. What is the treatment for lentigo maligna? In most cases, lentigo maligna should undergo surgical excision . This means cutting it out and repairing the defect by simply closing the wound and stitching it up, creating a flap or by skin grafting . Lentigo maligna has an unusually high risk of recurrence (up to 20%). For this reason, it is usually removed with a margin of healthy tissue, which can be difficult to achieve on facial skin. The ideal margin for all forms of melanoma in situ is 5-10mm, depending on how well defined are the edges of the lesion. Recommended margins for invasive melanoma are based on its thickness: it is 1 cm if less than 1 mm and 1-2 cm if the melanoma is over 1 mm in depth.

If the margin and extent of the lentigo maligna is unclear, mapped serial excision may be recommended (margin-controlled, Mohs micrographic surgery or 'slow Mohs'), in an attempt to remove all the malignant cells and to spare healthy skin. Other treatments for lentigo maligna may be considered if it is difficult to remove the lesion surgically, or surgery will be very deforming, or there is a major contraindication to surgery: Radiotherapy – superficial X-rays or electrons Cryotherapy – undertaken by an expert Imiquimod cream – not yet fully evaluated. However, these treatments do not offer as high cure rates as complete surgical excision. Because the risk of invasive melanoma is small, one option in very elderly patients with large lentigo maligna is to simply photograph and watch the lesion carefully, biopsying any areas suspicious of invasive disease because of clinical or dermoscopic change. What is the treatment for lentigo maligna melanoma? Lentigo maligna melanoma should be completely removed surgically.

If possible, there should be a 1 cm margin of normal skin around the tumour, but the margin may depend on the site of the lesion and how close it is to important structures like the mouth, eye or nose. If the local lymph nodes are enlarged due to melanoma, they should also be completely removed, which entails a major surgical procedure under general anaesthetic. Staging melanoma Melanoma staging means finding out if the melanoma has spread from its original site in the skin. Most melanoma specialists refer to the American Joint Committee on Cancer (AJCC) cutaneous melanoma staging guidelines (2009). In essence, the stages are: Stage Distant metastases have been detected What is the outlook for patients with melanoma? Lentigo maligna is not dangerous; it only becomes potentially life threatening if an invasive melanoma develops within it. Long term follow-up involves reviewing the treated area and full skin examination to identify new lesions of concern. If the lesion was invasive, regional lymph nodes should also be examined. It may be prudent to biopsy any lesion arising within or close to the excision site.

The risk of spread ( metastatic melanoma ) from invasive melanoma depends on several factors, but the main one is the thickness of the melanoma at the time it was surgically removed. The Melanoma Guidelines report that metastases are rare for melanomas <0.75mm and the risk for tumours 0.75–1 mm thick is about 5%. The risk steadily increases with thickness so that melanomas >4 mm result in a 10-year survival of around 50%, according to the American Joint Committee on Cancer (AJCC) statistics. Related information Noonan syndrome with multiple lentigines - Genetics Home Reference Noonan syndrome with multiple lentigines Description Noonan syndrome with multiple lentigines (formerly called LEOPARD syndrome) is a condition that affects many areas of the body. As the condition name suggests, Noonan syndrome with multiple lentigines is very similar to a condition called Noonan syndrome , and it can be difficult to tell the two disorders apart in early childhood. However, the features of these two conditions differ later in life.

The characteristic features of Noonan syndrome with multiple lentigines include brown skin spots called lentigines that are similar to freckles, heart defects, widely spaced eyes ( ocular hypertelorism ), a sunken chest (pectus excavatum) or protruding chest (pectus carinatum), and short stature. These features vary, however, even among affected individuals in the same family. Not all individuals with Noonan syndrome with multiple lentigines have all the characteristic features of this condition. The lentigines seen in Noonan syndrome with multiple lentigines typically first appear in mid-childhood, mostly on the face, neck, and upper body. Affected individuals may have thousands of small dark brown skin spots by the time they reach puberty. Unlike freckles, the appearance of lentigines has nothing to do with sun exposure. In addition to lentigines, people with this condition may have lighter brown skin spots called café-au-lait spots. Café-au-lait spots tend to develop before the lentigines, appearing within the first year of life in most affected people.

Of the people with Noonan syndrome with multiple lentigines who have heart defects, about 80 percent have hypertrophic cardiomyopathy , which is a thickening of the heart muscle that forces the heart to work harder to pump blood. The hypertrophic cardiomyopathy most often affects the lower left chamber of the heart ( the left ventricle ). Up to 20 percent of people with Noonan syndrome with multiple lentigines who have heart problems have a narrowing of the artery from the heart to the lungs (pulmonary stenosis). People with Noonan syndrome with multiple lentigines can have a distinctive facial appearance. In addition to ocular hypertelorism, affected individuals may have droopy eyelids ( ptosis ), thick lips, and low-set ears. Affected individuals also usually have an abnormal appearance of the chest; they either have pectus excavatum or pectus carinatum. At birth, people with Noonan syndrome with multiple lentigines are typically of normal weight and height, but in some, growth slows over time. This slow growth results in affected individuals being shorter than average, although less than half of people with Noonan syndrome with multiple lentigines have significantly short stature.

Other signs and symptoms of Noonan syndrome with multiple lentigines include hearing loss caused by abnormalities in the inner ear (sensorineural deafness), mild intellectual disability, and extra folds of skin on the back of the neck. Affected males often have genital abnormalities, which can include undescended testes (cryptorchidism) and a urethra that opens on the underside of the penis (hypospadias). These abnormalities may reduce the ability to have biological children (decreased fertility). Females with Noonan syndrome with multiple lentigines may have poorly developed ovaries and delayed puberty. Noonan syndrome with multiple lentigines is one of a group of related conditions collectively known as RASopathies. These conditions all have similar signs and symptoms and are caused by changes in the same cell signaling pathway. In addition to Noonan syndrome with multiple lentigines, the RASopathies include Noonan syndrome, cardiofaciocutaneous syndrome , Costello syndrome , neurofibromatosis type 1 , and Legius syndrome . Related Information Genetic Changes Mutations in one of several genes can cause Noonan syndrome with multiple lentigines.

Approximately 85 percent of individuals with this condition have mutations in the PTPN11 gene. Another 10 percent have mutations in the RAF1 gene. In rare cases, mutations in the BRAF or MAP2K1 gene have been found to cause this condition. The remaining individuals with Noonan syndrome with multiple lentigines do not have an identified mutation in any of these four genes. In these individuals, the cause of the condition is unknown. The PTPN11, RAF1, BRAF, and MAP2K1 genes all provide instructions for making proteins that are involved in important signaling pathways needed for the proper formation of several types of tissue during development. These proteins also play roles in the regulation of cell division , cell movement (migration), and cell differentiation (the process by which cells mature to carry out specific functions). A mutation in the PTPN11, RAF1, BRAF, or MAP2K1 gene leads to the production of a protein that functions abnormally, which impairs the protein's ability to respond to cell signals. A disruption in the regulation of systems that control cell growth and division leads to the characteristic features of Noonan syndrome with multiple lentigines.

Lentigo: Background, Pathophysiology, Epidemiology Pathophysiology Overview Background A lentigo is a small, sharply circumscribed, pigmented macule surrounded by normal-appearing skin. Histologic findings may include hyperplasia of the epidermis and increased pigmentation of the basal layer. A variable number of melanocytes are present; these melanocytes may be increased in number, but they do not form nests. Lentigines may evolve slowly over years, or they may be eruptive and appear rather suddenly. Pigmentation may be homogeneous or variegated, with a color ranging from brown to black. Multiple clinical and etiologic varieties exist. The distinction of a lentigo from other melanocytic lesions (eg, melanocytic nevi , melanoma ) and its role as a marker for ultraviolet damage and systemic syndromes is of major significance. A case-controlled study in France comparing 145 adults with multiple solar lentigines on the upper back and 145 matched control subjects found that multiple solar lentigines on the upper back and shoulders of adults may serve as clinical markers of past severe sunburn and may be used to identify a population at higher risk of developing cutaneous melanoma.

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Intense pulsed light in the treatment of non-aesthetic facial and neck vascular lesions: report of 85 cases. J Eur Acad Dermatol Venereol. 2011 Jan. 25(1):68-73. [Medline] . Media Gallery Thirteen-year-old Greek adolescent with xeroderma pigmentosum. Ephelides (ie, freckles) on the forearm of a 26-year-old redheaded patient. Woman with solar lentigo. Close-up view of a woman with solar lentigo. of 4

Question: What is the common name for "lentigo"?
Answer: Freckles