title: Merkel cell carcinoma: differences between sun-exposed and non-sun-exposed variants--a clinical analysis of 36 cases.
abstract: BACKGROUND
  There are few studies focusing on the clinical characteristics of Merkel cell carcinoma (MCC).
  
  
  OBJECTIVE
  To retrospectively analyze the clinical features of our patients and their relationship with sun exposure.
  
  
  METHODS
  Thirty-six patients diagnosed with MCC (20 men and 16 women, mean age 72.08 years) were included in the study.
  
  
  RESULTS
  21 patients developed MCC in sun-exposed skin and 15 patients in non-sun-exposed areas. MCC was >2 cm in 19 cases. Six of the 7 patients who died as a result of MCC had non-sun-exposed tumors. Only tumor size >2 cm significantly influenced survival (p = 0.033).
  
  
  CONCLUSIONS
  Sun-exposed lesions tended to be <2 cm in diameter and were more common in men, while non-sun-exposed tumors were larger, usually occurring in women and carrying a greater likelihood of death by MCC. Non-sun-exposed tumors usually present as fast-growing, multilobar nodular lesions with a smooth shiny surface.
authors.affiliation: Department of Dermatology, Bellvitge Hospital, Bellvitge Biomedical Research Institute, Barcelona, Spain.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Marcoval
authors.forename: Josep Ramon
authors.initials: JR
authors.lastname: Ferreres
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Penín
authors.forename: Diana
authors.initials: D
authors.lastname: Pérez
authors.forename: Joan Maria
authors.initials: JM
authors.lastname: Viñals
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D015266:Carcinoma, Merkel Cell / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012878:Skin Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D013030:Spain; D013472:Sunlight / Q000009:adverse effects*; D016019:Survival Analysis; D016896:Treatment Outcome