False negative sentinel lymph node biopsies in melanoma may result from deficiencies in nuclear medicine, surgery, or pathology.
OBJECTIVE
To investigate a cohort of melanoma patients with false negative (FN) sentinel node (SN) biopsies (SNBs) to identify the reasons for the FN result.


BACKGROUND
SNB is a highly efficient staging method in melanoma patients. However, with long-term follow-up FN SNB results of up to 25% have been reported.


METHODS
Seventy-four SNs from 33 patients found to have had an FN SNB were analyzed by reviewing the lymphoscintigraphy, surgical data, and histopathology, and by assessing nodal tissue using multimarker real-time quantitative reverse transcription (qRT) polymerase chain reaction, and antimony concentration measurements (as a marker of "true" SN status) using inductively coupled plasma mass spectroscopy.


RESULTS
Nine SNs (12%) from 9 patients (27%) had evidence of melanoma on histopathologic review. Twelve SNs (16%) from 10 patients (30%) were qRT(+). Four of these 12 SNs were positive on histopathology review and 8 were negative. Four patients (12%) were upstaged by qRT. Sixteen patients had their SNB histology, lymphoscintigraphy, and surgical data reviewed. Identifiable causes of the FN SNBs were not found after review of all modalities in 4 patients. SNs from all 4 patients had antimony levels indicative of an SN. Of the SNs evaluable by qRT, 1 was qRT(+) and 7 SNs from 2 patients were qRT(-).


CONCLUSIONS
An FN SN can occur because of deficiencies in nuclear medicine, surgery, or pathology. qRT can detect "occult" metastatic melanoma in SNs that have been identified as negative by histopathology.
Karim
Rooshdiya Z
RZ
Department of Anatomical Pathology, Sydney Cancer Centre, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
Scolyer
Richard A
RA
Li
Wei
W
Yee
Vivian S K
VS
McKinnon
J Gregory
JG
Li
Ling-Xi L
LX
Uren
Roger F
RF
Lam
Stella
S
Beavis
Alison
A
Dawson
Michael
M
Doble
Philip
P
Hoon
Dave S B
DS
Thompson
John F
JF
D000965:Antimony; D014408:Biomarkers, Tumor / Q000032:analysis; D003951:Diagnostic Errors; D005188:False Negative Reactions; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008545:Melanoma / Q000473:pathology*; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology*; D017556:Technetium Compounds
D014408:Biomarkers, Tumor; D019275:Radiopharmaceuticals; D017556:Technetium Compounds; C019096:technetium Tc 99m antimony sulfide; D000965:Antimony