You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Lentigo maligna melanoma and explain in detail?
Lentigo maligna melanoma is a melanoma that has evolved from a lentigo maligna,: 695  as seen as a lentigo maligna with melanoma cells invading below the boundaries of the epidermis. They are usually found on chronically sun damaged skin such as the face and the forearms of the elderly.
Lentigo maligna is the non-invasive skin growth that some pathologists consider to be a melanoma-in-situ.  A few pathologists do not consider lentigo maligna to be a melanoma at all, but a precursor to melanomas.  Once a lentigo maligna becomes a lentigo maligna melanoma, it is treated as if it were an invasive melanoma.

Presentation
An invasive tumor arising from a classical lentigo maligna.  Usually a darkly pigmented raised papule or nodule, arising from a patch of irregularly pigmented flat brown to dark brown lesion of sun exposed skin of the face or arms in an elderly patient.

Diagnosis
The first problem is difficulty. As lentigo malignas often present on severely sun damaged skin, it is frequently found amongst numerous pigmented lesions – thin seborrheic keratoses, lentigo senilis, lentigines. It is difficult to distinguish these lesions with the naked eye alone, and even with some difficulty using dermatoscopy. As the lentigo maligna is often very large, it often merges with, or encompasses other skin tumors – such as lentigines, melanocytic nevi, and seborrheic keratosis.
The second difficulty   is the biopsy technique