title: Nail apparatus melanoma: is trauma a coincidence? Is this peculiar tumor a real acral melanoma?
abstract: Nail Apparatus Melanoma (NAM) is rare, particularly in Caucasians. Understanding its pathogenesis and collecting epidemiologic data may be difficult due to its location and the exiguity of the case series of this cancer. Cutaneous melanoma has been thought related to UV radiation, and NAM is considered an acral variant of melanoma, even if the nail presents a specific anatomy. Little is reported about pathogenesis, except reports suggesting traumatic injuries as a causal factor. UV exposure is debated in nail melanoma because of its structure. The nail is, in fact, a unique structure with sun-exposed and non exposed melanocytes. NAM arises from the nail melanocytes, located in the nail matrix, which is the germinative part of the nail and composed of a proximal and distal portion. The proximal nail matrix lays under the proximal nail fold that covers it and is non-sun exposed, while the distant nail matrix, clinically visible as the lunula, is sun-exposed, though lying underneath the nail plate. According to these anatomical data, NAM is a distinct melanoma type, and studies need to classify it as acral melanoma or as a particular type of melanoma with its own pathogenesis and prognostic criteria. This study investigates potential risk factors of NAM, emphasizing (i) trauma and (ii) UV exposure among our NAM patients.
authors.affiliation: Internal Medicine Aging and Nephrologic Disease Department, Dermatology Division, Ospedale Sant'Orsola-Malpighi, Università degli Studi di Bologna, Bologna, Italy.
authors.forename: P A
authors.initials: PA
authors.lastname: Fanti
authors.forename: E
authors.initials: E
authors.lastname: Dika
authors.forename: C
authors.initials: C
authors.lastname: Misciali
authors.forename: S
authors.initials: S
authors.lastname: Vaccari
authors.forename: A
authors.initials: A
authors.lastname: Barisani
authors.forename: B M
authors.initials: BM
authors.lastname: Piraccini
authors.forename: G
authors.initials: G
authors.lastname: Cavrin
authors.forename: H I
authors.initials: HI
authors.lastname: Maibach
authors.forename: A
authors.initials: A
authors.lastname: Patrizi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000145:classification / Q000209:etiology*; D008875:Middle Aged; D009262:Nails; D012307:Risk Factors; D012878:Skin Neoplasms / Q000145:classification / Q000209:etiology*; D014466:Ultraviolet Rays