title: Clinical and dermoscopic features of combined cutaneous squamous cell carcinoma (SCC)/neuroendocrine [Merkel cell] carcinoma (MCC).
abstract: BACKGROUND
  Merkel cell carcinoma (MCC) is a neuroendocrine carcinoma, associated with Merkel cell polyomavirus. MCC admixed with squamous cell carcinoma (SCC) is unassociated with polyomavirus, and is genetically distinct.
  
  
  OBJECTIVE
  We sought to distinguish clinically and dermoscopically between MCC and SCC/MCC.
  
  
  METHODS
  We compared patient data for SCC/MCC (n = 26) and MCC (n = 20), and reviewed clinical and dermoscopic images (n = 9) of SCC/MCC.
  
  
  RESULTS
  Patients with SCC/MCC were older (median 76.5 vs 69 years) and more often male (77% vs 60%), and had more nonmelanoma skin cancer (85% vs 25%), malignant extracutaneous tumors (25% vs 5%), lymphoproliferative disorders (23% vs 10%), and immunodeficient/proinflammatory states (77% vs 35%). In all, 58% of SCC/MCC versus 10% of MCC were clinically diagnosed nonmelanoma skin cancer. Patients with SCC/MCC had more metastases (77% vs 40%), more treatment failures (53% vs 45%), shorter survival (41 vs 54 months), and more death from disease (50% vs 40%). SCC/MCC demonstrated marked scale (7/9), and telangiectasia (1/9). Dermoscopically, small dotted and short linear irregular peripheral vessels and central milky-red areas with large-diameter arborizing vessels were seen.
  
  
  CONCLUSIONS
  The rarity of SCC/MCC limits available data.
  
  
  CONCLUSIONS
  SCC/MCC is aggressive, arising within elderly patients' chronically ultraviolet-exposed skin, often in the setting of immunosuppression or inflammation. Dermoscopically, polymorphous vessels in lesions suspicious for nonmelanoma skin cancer are suggestive.
authors.affiliation: Department of Dermatology, New York-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York.
authors.forename: Andrea Luísa
authors.initials: AL
authors.lastname: Suárez
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Peter
authors.initials: P
authors.lastname: Louis
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Kitts
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Klaus
authors.initials: K
authors.lastname: Busam
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Myskowski
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Wong
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Chih-Shan Jason
authors.initials: CS
authors.lastname: Chen
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Philip
authors.initials: P
authors.lastname: Spencer
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Mario
authors.initials: M
authors.lastname: Lacouture
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York. Electronic address: pulitzem@mskcc.org.
authors.forename: Melissa P
authors.initials: MP
authors.lastname: Pulitzer
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D016208:Databases, Factual; D046169:Dermoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D012878:Skin Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D015996:Survival Rate; D016896:Treatment Outcome
keywords: Merkel cell; biphenotypic; dermoscopy; neuroendocrine carcinoma; polyomavirus; ultraviolet signature