title: Merkel cell carcinoma in the setting of chronic lymphocytic leukemia.
abstract: BACKGROUND
  Merkel cell carcinoma (MCC) is a rare, aggressive, primary skin cancer that usually occurs in elderly white people on the sun-exposed areas of skin. Chronic lymphocytic leukemia (CLL) is a low-grade, clonal, B-cell, lymphoproliferative disorder that also usually affects older adults. CLL has been associated with multiple other secondary malignancies, especially skin cancer.
  
  
  OBJECTIVE
  To further understand the characteristics and behavior of MCC in the setting of concomitant CLL.
  
  
  METHODS
  We identified patients with diagnoses of both MCC and CLL who were seen at the Mayo Clinic (Rochester, MN) from January 1, 1976, to December 31, 2008, and retrospectively reviewed the charts of the identified patients.
  
  
  RESULTS
  Seven patients received diagnoses of MCC and CLL. Five of these patients appeared to have higher rates of recurrence, metastasis, and mortality than patients with MCC but not CLL.
  
  
  CONCLUSIONS
  MCC may behave more aggressively in the setting of concomitant CLL, but more studies are needed to definitively evaluate the characteristics and behavior of MCC in these patients.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Khezri
authors.forename: Jerry D
authors.initials: JD
authors.lastname: Brewer
authors.forename: Amy L
authors.initials: AL
authors.lastname: Weaver
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015266:Carcinoma, Merkel Cell / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D016609:Neoplasms, Second Primary / Q000473:pathology*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000401:mortality / Q000473:pathology*