RT Book, Section
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.
SR Print(0)
ID 1145756295
T1 Noncutaneous Melanoma
T2 Textbook of Complex General Surgical Oncology
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9780071793315
LK hemonc.mhmedical.com/content.aspx?aid=1145756295
RD 2024/04/24
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.