Carbon dye staining of sentinel lymph nodes facilitates microstaging of colon cancer patients.
BACKGROUND
Carbon dye, when peritumourally injected, permanently marks the drainage site of sentinel lymph nodes (SLN). The objective of the current study was to evaluate whether the use of carbon dye facilitated the detection of small nodal tumour infiltrates in colon cancer patients.


METHODS
In a prospective trial, 19 patients underwent open, oncological resections of localized colon cancer and SLN procedure according to a standardized protocol. Isosulfan blue 1% and sterile filtered carbon dye (mixed 1:1) were injected into the subserosa circumferentially around the tumour. Lymph nodes staining blue were marked as SLN. Serial sections of each SLN were stained with hematoxylin and eosin (H&E) and with the pancytokeratin marker AE1/AE3. The intranodal presence and site of carbon particles were noted and compared with the location of possible tumour infiltrates.


RESULTS
Identification of at least one SLN was successful in 18 patients (identification rate 95%). Four patients (22%) were pN+, 11 (61%) were pN0(i-). Three patients (17%) were upstaged from pN0(i-) to pN0(i+) as isolated tumour cells were detected in their SLN: in two (11%) of the three patients, carbon dye and isolated tumour cells were found in the same nodal compartment, hence facilitating the recognition of isolated tumour cells by the pathologist.


CONCLUSIONS
The use of carbon dye in the SLN procedure for colon cancer may facilitate the detection of small nodal tumour infiltrates.
Viehl
Carsten T
CT
Department of Surgery, University Hospital Basel, Spitalstrasse 21, Basel, 4031, Switzerland.
Guller
Ulrich
U
Hamel
Christian T
CT
Riehle
Hans-Martin
HM
Plaass
Christian
C
Marti
Walter R
WR
Oertli
Daniel
D
Zuber
Markus
M
D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon; D016009:Chi-Square Distribution; D003110:Colonic Neoplasms / Q000473:pathology*; D004396:Coloring Agents; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D009367:Neoplasm Staging / Q000379:methods*; D011446:Prospective Studies; D012394:Rosaniline Dyes; D013194:Staining and Labeling / Q000379:methods*
D004396:Coloring Agents; D012394:Rosaniline Dyes; C025484:iso-sulfan blue; D002244:Carbon