The first problem is difficulty. As<unk><unk> s often present on severely sun damaged skin, it is frequently found amongst numerous pigmented lesions – thin seborrheic keratoses,<unk>  senilis,<unk> nes. It is difficult to distinguish these lesions with the naked eye alone, and even with some difficulty using dermatoscopy. As the<unk><unk>  is often very large, it often merges with, or encompasses other skin tumors – such as<unk> nes, melanocytic nevi, and seborrheic keratosis. The second difficulty is the biopsy technique. Even though excisional biopsy (removing the entire lesion) is ideal, and advocated by pathologists, practical considerations may indicate that this should not be done. These tumors are often large and presenting on the facial area. Excision of such large tumor would be absolutely contraindicated if the lesion's identity is uncertain. The preferred method of diagnosis is by using a shave biopsy because punch biopsies give up to an 80% false negative rate. While one section of the tumor might show benign melanocytic nevus, another section might show features concerning of severe cellular atypia. When cellular atypia is noted, a pathologist might indicate that the entire lesion should be removed. It is at this point that one can comfortably remove the entire lesion, thus confirming the final diagnosis of<unk><unk> . Despite the high false negative rate, punch biopsies are often used and the size of the punch biopsy can vary from 1 mm to 2 mm, but it is preferred to use a punch 1.5 mm or larger. Representative samples of the most atypical part of the nevus should be biopsy, often by the aid of dermatoscopy. File:Lentigo<unk>  Melanoma Left Central Malar Cheek.Lentigo<unk>  Melanoma, Left Central Malar Cheek marked for biopsy
Lentigo maligna melanoma
Acral lentiginous melanoma
Nodular melanoma
Superficial spreading melanoma
Pseudomelanoma
Polypoid melanoma
Animal-type melanoma
Amelanotic melanoma