title: Impact of sentinel lymph node biopsy in patients with Merkel cell carcinoma: results of a prospective study and review of the literature.
abstract: OBJECTIVE
  Merkel cell carcinoma (MCC) is the most aggressive of the cutaneous malignancies, showing a propensity to spread to regional lymph nodes (LNs). The aim of this prospective study was to examine the feasibility and clinical impact of sentinel lymph node biopsy (SLNB) in this cutaneous malignancy.
  
  
  METHODS
  The study population comprised 23 patients with stage I MCC (median age 70 years, range 50-85 years). Lymphoscintigraphic mapping with( 99 m)Tc-nanocolloid was performed in all patients. Sentinel lymph nodes (SLNs) were identified, excised and analysed in serial sections by conventional histopathology and cytokeratin-20 immunohistochemistry.
  
  
  RESULTS
  Metastatic disease was determined in the SLNs of 11 patients (47.8%). Elective lymph node dissection (ELND) was performed in eight of these 11 patients, four of whom had additional positive LNs. During follow-up (median 36.1 months, range 3-79 months), seven of the 23 patients (30%) relapsed: four had a local recurrence and three, in-transit metastases. Recurrence developed in two SLN-negative patients with local LN metastases and in one SLN-positive patient with distant metastases. This patient died, representing the only tumour-related death in our sample. Median survival was 49.1 and 35.5 months for SLN-negative and SLN-positive patients, respectively. This difference was not statistically significant (p=0.3452).
  
  
  CONCLUSIONS
  SLNB allows for exact nodal staging in patients with MCC. Whether additional ELND is of further benefit remains unclear.
authors.affiliation: Clinic for Nuclear Medicine, Charité, Universitätsmedizin Berlin, Schumannstrasse 20-21, 10117, Berlin, Germany. sofianem@web.de
authors.forename: Sofiane
authors.initials: S
authors.lastname: Maza
authors.forename: Uwe
authors.initials: U
authors.lastname: Trefzer
authors.forename: Maja
authors.initials: M
authors.lastname: Hofmann
authors.forename: Silke
authors.initials: S
authors.lastname: Schneider
authors.forename: Christiane
authors.initials: C
authors.lastname: Voit
authors.forename: Thomas
authors.initials: T
authors.lastname: Krössin
authors.forename: Andreas
authors.initials: A
authors.lastname: Zander
authors.forename: Heike
authors.initials: H
authors.lastname: Audring
authors.forename: Wolfram
authors.initials: W
authors.lastname: Sterry
authors.forename: Dieter L
authors.initials: DL
authors.lastname: Munz
mesh_terms: D000368:Aged; D015266:Carcinoma, Merkel Cell / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology* / Q000556:secondary*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology* / Q000556:secondary*