Prognosis
As of 2020, no treatment guidelines exist for NPD and no empirical studies have been conducted on specific NPD groups to determine efficacy for psychotherapies and pharmacology.The presence of NPD in patients undergoing psychotherapy for the treatment of other mental disorders is associated with slower treatment progress and higher dropout rates. Epidemiology
As of 2018, overall prevalence is estimated to range from 0.8% to 6.2%. In 2008 under the DSM-IV, lifetime prevalence of NPD was estimated to be 6.2%, with 7.7% for men and 4.8% for women, with a 2015 study confirming the gender difference. In clinical settings, prevalence estimates range from 1% to 15%. The occurrence of narcissistic personality disorder presents a high rate of comorbidity with other mental disorders. History
The term "narcissism" comes from a first century (written in the year 8 AD) book by the Roman poet Ovid. Metamorphoses Book III is a myth about two main characters, Narcissus and Echo. Narcissus is a handsome young man who spurns the advances of many potential lovers. When Narcissus rejects the nymph Echo, named this way because she was cursed to only echo the sounds that others made, the gods punish him by making him fall in love with his own reflection in a pool of water. When Narcissus discovers that the object of his love cannot love him back, he slowly pines away and dies.The concept of excessive selfishness has been recognized throughout history. In ancient Greece, the concept was understood as hubris.
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. Even though excisional biopsy (removing the entire lesion) is ideal, and advocated by pathologists, practical considerations may indicate that this should not be done.