Lentigo

A lentigo is a small pigmented macule with a sharply circumscribed border, There are multiple clinical and etiologic forms. Lentigines are often initially identified shortly after birth, although they may appear later in childhood. Certain varieties are associated with systemic abnormalities. Histologic findings include epidermal hyperplasia with increased pigmentation of the basal layer Lentigo is derived from the Latin word lens meaning lentil.1 Pigmentation varies from homogeneous to variegated and from brown to black. Lentigines may evolve slowly over a number of years, or they may be eruptive, appearing in a short period. They can be either solitary or multiple, occurring anywhere on the body depending on the type of lentigo.2 Certain varieties have associated systemic manifestations. The clinical distinction of a lentigo, as opposed to other melanocytic lesions such as melanocytic nevi or melanoma, is of major significance because of its role as a marker for UV damage or systemic syndromes.3

Epidemiology

Lentigines are commonly found in people around the world. Lentigo simplex is the most common form of lentigo, but its frequency has yet to be determined.4 A study conducted by Alper and Holmes5 revealed multiple lentigines in 18.5% of 492 black newborns and in 0.04% of 2682 white newborns. However, histologic confirmation of these lesions was lacking.

Clinical Manifestations

The clinical presentation of lentigines varies depending on their type. Various forms of lentigines appear in children and are described as follows.

Lentigo Simplex-Lentigo simplex, also referred to as simple or juvenile lentigo, is the most common form of lentigo. The lentigines are similar in appearance to solar lentigines or "liver spots," but they lack the predilection for sun exposed areas of the body. Additionally, simple lentigines usually appear initially in childhood, as opposed to solar lentigines, which appear in adulthood.6,7 Simple lentigines are round to oval, asymptomatic macules measuring 3 to 15 mm in diameter.8 The margins are either jagged or smooth, and the color ranges from brown to black with even distribution of pigmentation. Lesions occur anywhere on the body and are generally few.2

Lentigines Profusa-Lentigines profusa, or generalized lentigines, is characterized by numerous lentigines without signs of associated abnormalities or triggering factors. The clinical appearance is similar to ephelides, but the distribution is widespread.2 The areas most commonly involved...