Lentigo maligna
See also in: Hair and ScalpAlerts and Notices
Synopsis

The natural history of lentigo maligna is that of gradual, asymmetric, radial growth. The majority of lesions are > 6 mm, macular, and variably pigmented with ill-defined, irregular borders. Lentigo maligna has a particular predilection for the nose and cheeks.
Approximately 5% are thought to progress to lentigo maligna melanoma, although it may be several years before this vertical growth phase occurs.
Lentigo maligna and lentigo maligna melanoma have been associated with nonmelanoma skin cancers, Werner syndrome, oculocutaneous albinism, and xeroderma pigmentosa.
Codes
ICD10CM:D03.9 – Melanoma in situ, unspecified
SNOMEDCT:
302836005 – Lentigo maligna
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Lentigo maligna melanoma
- Nevus
- Atypical nevus
- Solar lentigo
- Melanoma
- Melasma
- Seborrheic keratosis
- Pigmented basal cell carcinoma
- Pigmented actinic keratosis
- Pigmented squamous cell carcinoma in situ (Bowen disease)
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Therapy
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References
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Last Reviewed:01/02/2019
Last Updated:10/27/2021
Last Updated:10/27/2021


Overview
Lentigo maligna is a form of melanoma skin cancer that is also referred to as "melanoma in situ." It has not invaded the second layer of skin. This means that the skin cells have been damaged enough to become cancerous but not to metastasize (ie, invade the bottom layer of skin and spread to other areas of the body).Lentigo maligna is most commonly found on sun-exposed areas of skin. This is because the sun produces ultraviolet (UV) radiation, which can damage skin cells. When significant damage has been done, skin cells may become cancerous.
If lentigo maligna is not treated, it can develop into invasive melanoma, which can metastasize (spread to other areas of the body).
If your physician suspects that a lesion may be melanoma, he or she will perform a skin biopsy (a simple procedure to surgically remove the lesion) and then examine a sample of the biopsy under a microscope. Examining the skin under a microscope will allow the physician to establish a precise diagnosis.