TY - CHAP M1 - Book, Section TI - Noncutaneous Melanoma A1 - Henderson, Michael A. A1 - Spillane, John A1 - Gyorki, David A2 - Morita, Shane Y. A2 - Balch, Charles M. A2 - Klimberg, V. Suzanne A2 - Pawlik, Timothy M. A2 - Posner, Mitchell C. A2 - Tanabe, Kenneth K. Y1 - 2018 N1 - T2 - Textbook of Complex General Surgical Oncology AB - During embryogenesis, melanocytes migrate from the neural crest and eventually are widely distributed throughout skin, mucosa, and other sites. Melanomas arising in noncutaneous sites are a heterogenous group that account for less than 1.5% of all melanomas. Sinonasal and vulval melanomas account for the majority of these cases; however, other sites include the uveal tract and the mucosa of the respiratory, genitourinary, and gastrointestinal tracts and glaborous (nonhair bearing) skin. Apart from some orbital melanomas, these sites are not exposed to ultraviolet (UV) radiation and recent genomic analyses indicate that they lack the typical signature of UV exposure seen in many cutaneous melanomas. Recent genomic studies have also identified unique mutations in a proportion of noncutaneous melanomas that distinguish them from cutaneous melanomas. In very rare cases, melanomas may arise in unusual mucosal sites such as the bowel, bronchus, and gall bladder. In these situations, it may not be possible to determine whether these are truly primary lesions or isolated metastases from an unknown primary. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - accesssurgery.mhmedical.com/content.aspx?aid=1145756295 ER -