RT Book, Section
A1 Lonsdorf, Anke S.
A1 Hadaschik, Eva N.
A2 Kang, Sewon
A2 Amagai, Masayuki
A2 Bruckner, Anna L.
A2 Enk, Alexander H.
A2 Margolis, David J.
A2 McMichael, Amy J.
A2 Orringer, Jeffrey S.
SR Print(0)
ID 1161335469
T1 Squamous Cell Carcinoma and Keratoacanthoma
T2 Fitzpatrick's Dermatology, 9e
YR 2019
FD 2019
PB McGraw-Hill Education
PP New York, NY
SN 9780071837798
LK accessmedicine.mhmedical.com/content.aspx?aid=1161335469
RD 2024/04/16
AB AT-A-GLANCESquamous  cell  carcinoma  (SCC)  is  the  second  most  common  skin  cancer,  after  basal  cell  carcinoma,  in  immunocompetent  white  individuals,  and  the  most  common  skin  cancer  in  immunosuppressed  organ  transplantation  recipients  worldwide.SCC  development  in  the  skin  is  considered  a  multistep  process,  most  invasive  SCCs  develop  from  preinvasive  lesions  or  in  situ  tumors  such  as  actinic  keratosis  or  Bowen  disease.Risk  factors  for  SCC  include  ultraviolet  (UV)  radiation,  genetic  predisposition,  physical  and  chemical  carcinogens,  immunosuppression,  drugs,  viral  infection,  chronic  inflammation,  and  chronic  injury  of  the  skin.Diagnosis  of  SCC  is  established  histologically.  Histologic  subtypes  include  spindle-cell,  acantholytic,  verrucous,  and  desmoplastic  SCCs,  and  keratoacanthoma.High-risk  features  for  local  recurrence  and  the  development  of  metastatic  disease  include  >2  mm  thickness;  Clark  level  higher  than  IV;  perineural  invasion;  lip  or  ear  as  primary  site;  poorly  or  undifferentiated  tumor.The  primary  mode  of  therapy  for  localized  SCC  is  complete  surgical  excision,  preferentially  microscopically  controlled  surgery  (Mohs  surgery).  Nonsurgical  interventions  include  topical  therapy,  and  for  locally  advanced,  unresectable  or  metastatic  SCC,  radiation  therapy  and  systemic  treatment  with  chemotherapy  or  targeted  therapy.Primary  prevention  for  the  development  of  SCC  is  based  on  decreasing  UV  radiation  exposure  and  concomitant  risk  factors,  and  the  effective  treatment  of  precursor  lesions.  Systemic  retinoids,  niacinamide,  as  well  as  change  of  the  immunosuppressive  regimen  in  solid-organ  transplantation  recipients  may  be  options  for  the  secondary  prevention  of  SCC  in  high-risk  patients.