Lentigo

from Wikipedia, the free encyclopedia
Classification according to ICD-10
L81.4 Lentigo
ICD-10 online (WHO version 2019)

A lentigo ( Latin for lens-shaped spot , plural lentigines or lentigenes ), sometimes also called nevus lenticularis , describes in dermatology a small, sharply defined spot on the skin caused by an increased occurrence of melanocytes or increased melanin formation . It is a particular subtype of pigmented, circumscribed, benign anomalies of the skin ( pigmented nevi ), commonly known as "moles" or " liver spots ".

Lentigo simplex

Lentigo simplex (synonym: Lentigo juvenilis ), the classic "mole", often occurs in childhood in areas exposed to the sun.

Purely macroscopically, a lentigo simplex can hardly be distinguished from a junctional nevus . Both skin lesions are flat, brown to dark brown, round or oval, and usually smaller than 5 mm in diameter. The difference only becomes clear in the histological examination, because there are no nests of nevus cells in the lentigo simplex as in the junctional nevi , but only an increased number of melanocytes .

In contrast to a junctional nevus, a lentigo simplex can not develop into a malignant melanoma .

Lentigo solaris

In Lentigo solaris (synonyms: Lentigo senilis , age spots) there is a proven connection between chronic sun exposure and the development of Lentigenes solares, in direct relation to the duration and intensity of the sun exposure. Lentigenes solares develop progressively in late adulthood and can no longer be reduced by local measures or sun protection. Light skin types are most commonly affected.

The lentigo solaris is a flat, brown lesion at the level of the skin and has a round, blotchy or star-shaped, but always sharply defined, outline. It can reach up to 5 cm in diameter. In terms of color, it is usually piebald and irregularly brownish in pigment. There is a reactive proliferation of melanocytes and melanin storage in the basal layer of the epidermis . Lentigenes solares only occur in areas exposed to the sun.

The “age spots” themselves are harmless, but they can be confused with early forms of melanoma and, on the other hand, are an expression of skin damage caused by excessive sun exposure ( dermatoheliosis ), which in turn predisposes to the development of actinic keratoses , basaliomas , squamous cell carcinomas and melanomas.

However, since there is a subtype of malignant melanoma ( lentigo maligna melanoma) that has clear similarities and develops from lentigo maligna , medical / dermatological assessment of age spots is recommended.

Especially people with light skin types should protect themselves from the effects of the sun from childhood. Excessive exposure to the sun should be avoided and effective sunscreens should be used. Local overproduction of melanin, which is responsible for the development of brown spots, can be specifically inhibited by the active ingredient rucinol . However, there are indications that the use of local gels or lotions can prevent erythema solare ("sunburn"), but not sun-induced immunosuppression .

Lentiginoses

As lentigines are syndromes referred associated with a large number of "liver spots", so many lesions that the simplex lentigo similar. The distribution of the lentigenes is characteristic of each of the following syndromes. The lips or genital mucosa are usually particularly affected.

Other forms

  • The lentigo maligna is an exception with respect to the other Lentigenes is because they obligate precancerous no longer among the nevi is counted but a melanoma in situ corresponds to the epidermis.
  • Lentigo malignant melanoma accounts for around 10% of melanomas
  • The name Lentigo aestiva refers to ephelids ("freckles").

literature

  • Thomas B. Fitzpatrick, Klaus Wolff (ed.): Atlas and synopsis of clinical dermatology: common and threatening diseases . 3. Edition. McGraw-Hill, New York; Frankfurt a. M., 1998, ISBN 0-07-709988-5 .
  • Ernst G. Jung, Ingrid Moll (Ed.): Dermatology . 5th edition. Thieme, Stuttgart, 2003, ISBN 3-13-126685-6

Web links