Lentigo Differential Diagnoses

Updated: Jun 06, 2022
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: William D James, MD  more...
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Diagnostic Considerations

Consider melanoma and lentigo maligna melanoma. Also consider porokeratosis. [30]

Ephelides (ie, freckles) are light brown macules that occur on the sun-exposed areas of the face, dorsum of the hands, and forearms. These lesions are more common in individuals with light hair, especially red hair, and light skin, but they can also occur in people with dark hair and skin. They usually appear in the summer months, and they may persist throughout life. Examination of the skin with a Wood lamp may reveal ephelides that are not evident in ordinary light. The distribution is symmetric, and the lesions may be either sparse or dense. The color of the lesions tends to deepen after sun exposure, ranging from pale yellow to brown or even black. The borders are well defined and irregular, and the lesions can have a diameter as large as 5 mm. In people with natural ephelides, a single UVB exposure can induce the formation of additional ephelides.

Diagnostic key points for lentigo are noteworthy to distinguish it from lentigo maligna, the former having findings that include annular-granular structures and a gray pseudonetwork. [31] However, pigmented actinic keratosis, lichen planus–like keratosis, and lentigo maligna may be challenging to clinically distinguish, making the differential diagnosis difficult. [32]  The distinction between lentigo maligna and solar lentigo may be challenging. Digital epiluminescence microscopy–specific criteria may facilitate distinction. [33]  Spontaneous hair repigmentation of physiologically white or gray hair is rare occurrence and may portend lentigo maligna in elderly individuals. [34]

Large cell acanthoma may be a variant of solar lentigo. [35]

Differential Diagnoses