Impact of sentinel lymph node biopsy in patients with Merkel cell carcinoma: results of a prospective study and review of the literature.
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.
Maza
Sofiane
S
Clinic for Nuclear Medicine, Charité, Universitätsmedizin Berlin, Schumannstrasse 20-21, 10117, Berlin, Germany. sofianem@web.de
Trefzer
Uwe
U
Hofmann
Maja
M
Schneider
Silke
S
Voit
Christiane
C
Krössin
Thomas
T
Zander
Andreas
A
Audring
Heike
H
Sterry
Wolfram
W
Munz
Dieter L
DL
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*