A lentigo () (plural lentigines, ) is a small pigmented spot on the skin with a clearly defined edge, surrounded by normal-appearing skin. It is a harmless (benign)
hyperplasia
Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of Tissue (biology), organic tissue that results from ...
of
melanocytes
Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea),
the inner ear,
vaginal epithelium, meninges,
bones,
and hea ...
which is linear in its spread. This means the
hyperplasia
Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of Tissue (biology), organic tissue that results from ...
of melanocytes is restricted to the cell layer directly above the
basement membrane of the
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...
where melanocytes normally reside. This is in contrast to the "nests" of multi-layer melanocytes found in
moles (melanocytic
nevi). Because of this characteristic feature, the adjective "lentiginous" is used to describe other skin lesions that similarly proliferate linearly within the basal cell layer.
[''Random House Webster's Unabridged Dictionary.'' Random House, Inc. 2001. p. 1101. .][''Robbins and Cotran Pathologic Basis of Disease'' Elsevier. 2005. p. 1232. .]
Diagnosis
Conditions characterized by lentigines include:
*
Lentigo simplex
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Solar lentigo (Liver spots)
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PUVA lentigines
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Ink spot lentigo
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LEOPARD syndrome
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Mucosal lentigines
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Multiple lentigines syndrome
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Moynahan syndrome
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Generalized lentiginosis
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Centrofacial lentiginosis
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Carney complex
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Inherited patterned lentiginosis in black persons
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Partial unilateral lentiginosis
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Peutz–Jeghers syndrome
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Lentigo maligna
*
Lentigo maligna melanoma
*
Acral lentiginous melanoma
Differential diagnosis
Lentigines are distinguished from
freckles (ephelis) based on the proliferation of melanocytes. Freckles have a relatively normal number of melanocytes but an increased ''amount'' of
melanin. A lentigo has an increased ''number'' of melanocytes. Freckles will increase in number and darkness with sunlight exposure, whereas lentigines will stay stable in their color regardless of sunlight exposure.
Treatment
Lentigines by themselves are benign,
however one might desire the removal or treatment of some of them for cosmetic purposes. In this case they can be removed surgically,
or lightened with the use of topical depigmentation agents. Some common depigmentation agents such as azelaic acid and kojic acid seem to be inefficient in this case, however other agents might work well (4% hydroquinone, 5% topical cysteamine, 10% topical ascorbic acid
).
See also
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Freckle
*
List of skin diseases
*
Mole
*
Skin disease
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, Nail (anatomy), nails, and related muscle and glands. The major funct ...
*
Skin lesion
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this ...
References
External links
{{Skin tumors, nevi and melanomas
Melanocytic nevi and neoplasms
Disturbances of human pigmentation