Lentigo maligna

Lentigo maligna - very high mag

SOX10 immunohistochemistry of lentigo maligna

Lentigo Maligna Melanoma Left Central Malar Cheek

Scars from skin flap

Lentigo Maligna is a melanoma in situ that consists of malignant cells but does not invade the surrounding tissues. It is considered an early form of skin cancer, specifically a subtype of melanoma, which is the most serious type of skin cancer. Lentigo maligna typically develops in older adults, with a higher prevalence in those with a long history of sun exposure, indicating a strong link between UV radiation and the development of this condition.

Etiology and Risk Factors

The primary cause of lentigo maligna is prolonged exposure to ultraviolet (UV) radiation, which damages the DNA in skin cells. This damage can lead to mutations that cause the cells to grow uncontrollably, forming a tumor. Risk factors include having a fair complexion, being older, having a history of intense sun exposure or sunburns, living in sunny or high-altitude climates, and having a history of using tanning beds.

Clinical Presentation

Lentigo maligna presents as a slowly enlarging flat patch of discolored skin, usually brown, black, or tan, and often has an irregular border. It most commonly appears on the face, especially on the cheeks, nose, forehead, and ears, areas that receive the most sun exposure over the years. The lesion may be mistaken for a freckle or a liver spot due to its appearance.

Diagnosis

Diagnosis of lentigo maligna is primarily based on a physical examination and a biopsy of the lesion. Dermoscopy, a non-invasive imaging technique, can also be used to examine the skin's surface for signs of melanoma. Histopathological examination of the biopsy sample is the definitive method for diagnosing lentigo maligna, allowing for the assessment of the presence of malignant cells confined to the epidermis.

Treatment

The main treatment for lentigo maligna is surgical removal. The goal is to excise the lesion entirely, with a margin of healthy tissue around it to ensure all malignant cells are removed. In cases where surgery is not possible or preferred, alternative treatments may include cryotherapy, laser therapy, or topical chemotherapy. Regular follow-up is essential to monitor for recurrence or the development of invasive melanoma.

Prognosis

The prognosis for lentigo maligna is generally favorable if detected and treated early, before it progresses to invasive melanoma. However, the risk of progression exists, underscoring the importance of early detection and treatment.

Prevention

Prevention of lentigo maligna involves minimizing UV radiation exposure by seeking shade, wearing protective clothing, and applying broad-spectrum sunscreen with a high SPF. Regular skin examinations by a healthcare professional and self-examinations are crucial for early detection of lentigo maligna and other forms of skin cancer.