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 organic tissue that results from cell proliferati ...

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 heart. ...

which is linear in its spread. This means the

of melanocytes is restricted to the cell layer directly above the

basement membrane The basement membrane is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between Epithelium, epithelial tissues including mesot ...

of the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

where melanocytes normally reside. This is in contrast to the "nests" of multi-layer melanocytes found in

moles Moles can refer to: *Moles de Xert, a mountain range in the Baix Maestrat comarca, Valencian Community, Spain *The Moles (Australian band) *The Moles, alter ego of Scottish band Simon Dupree and the Big Sound People *Abraham Moles, French engineer ...

(melanocytic

nevi Nevus (plural nevi) is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa. The term originates from ''nævus'', which is Latin for "birthmark"; however, a nevus can be either congenital (present at bir ...

). 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 Lentigo simplex is the most common form of lentigo. A single lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur ...

Solar lentigo Solar may refer to: Astronomy * Of or relating to the Sun ** Solar telescope, a special purpose telescope used to observe the Sun ** A device that utilizes solar energy (e.g. " solar panels") ** Solar calendar, a calendar whose dates indica ...

(Liver spots) *

PUVA lentigines PUVA lentigines is a cutaneous condition caused by PUVA therapy PUVA (psoralen and UVA) is an ultraviolet light therapy treatment for skin diseases: eczema, psoriasis, graft-versus-host disease, vitiligo, mycosis fungoides, large plaque parapso ...

Ink spot lentigo Ink spot lentigo is a cutaneous condition characterized by skin lesions commonly occurring on the shoulders. These lesions often cause alarm but are benign. They are an indication of excessive sun exposure so although ink spot lentigo is not premal ...

LEOPARD syndrome Noonan syndrome with multiple lentigines (NSML) which is part of a group called Ras/MAPK pathway syndromes, is a rare autosomal dominant, multisystem disease caused by a mutation in the protein tyrosine phosphatase, non-receptor type 11 gene (''PT ...

Mucosal lentigines Mucosal lentigines is a cutaneous condition characterized by light brown macules on mucosal surfaces. See also * Lentigo * Skin lesion A skin condition, also known as cutaneous condition, is any medical condition that affects the integume ...

Multiple lentigines syndrome Multiple may refer to: Economics *Multiple finance, a method used to analyze stock prices *Multiples of the P/E, price-to-earnings ratio *Chain stores, are also referred to as 'Multiples' *Box office multiple, the ratio of a film's total gross to ...

Moynahan syndrome Moynahan is a family name with Irish origin and may refer to: ;People * Bernard Thomas Moynahan Jr. (1918–1999), an American federal judge *Brian Moynahan, an English writer *Bridget Moynahan, an American model and actress *Julian Moynahan (1925- ...

Generalized lentiginosis Generalized lentiginosis is a cutaneous condition that will occasionally present without other associated abnormalities. It may be caused by carney complex, Noonan syndrome with multiple lentigines or Peutz–Jeghers syndrome. See also * Lentig ...

Centrofacial lentiginosis Centrofacial lentiginosis is a cutaneous condition characterized by lentigines on the nose and adjacent cheeks. The condition is associated with sacral hypertrichosis, developmental delay, seizures, absent middle incisors, skeletal, abnormalities, ...

Carney complex Carney complex and its subsets LAMB syndrome and NAME syndrome are autosomal dominant conditions comprising myxomas of the heart and skin, hyperpigmentation of the skin (lentiginosis), and endocrine overactivity. It is distinct from Carney's triad ...

Inherited patterned lentiginosis in black persons Inherited patterned lentiginosis is an inherited skin condition that results in widespread small, flat areas of more-pigmented skin with clearly defined borders, generally noticed when the affected person is an infant or young child. The inherita ...

Partial unilateral lentiginosis Partial unilateral lentiginosis is a cutaneous condition characterized by lentigines located on only one half of the body. See also * Lentigo * List of cutaneous conditions References

Melanocytic nevi and neoplasms {{Cutaneous-condit ...

Peutz–Jeghers syndrome Peutz–Jeghers syndrome (often abbreviated PJS) is an autosomal dominant genetic disorder characterized by the development of benign hamartomatous polyps in the gastrointestinal tract and hyperpigmented macules on the lips and oral mucosa (melanos ...

Lentigo maligna Lentigo maligna is where melanocyte cells have become malignant and grow continuously along the stratum basale of the skin, but have not Invasion (cancer), invaded below the epidermis. Lentigo maligna is not the same as lentigo maligna melanoma, as ...

Lentigo maligna melanoma Lentigo maligna melanoma is a melanoma that has evolved from a lentigo maligna, as seen as a lentigo maligna with melanoma cells invading below the boundaries of the epidermis. Last Update: May 18, 2019. They are usually found on chronically sun d ...

Acral lentiginous melanoma Acral lentiginous melanoma is an aggressive type of skin cancer that is not caused by sunlight. Melanoma is a group of serious skin cancers that arise from pigment cells (melanocytes); acral lentiginous melanoma is a kind of lentiginous skin me ...

Differential diagnosis

Lentigines are distinguished from

freckles Freckles are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion. Freckles do not have an increased number of the melanin-producing cells, or melanocytes, but instead have melanocytes that ...

(ephelis) based on the proliferation of melanocytes. Freckles have a relatively normal number of melanocytes but an increased ''amount'' of

melanin Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...

. 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).

References

External links

{{Skin tumors, nevi and melanomas Melanocytic nevi and neoplasms Disturbances of human pigmentation