A Prospective Study of False-Positive Diagnosis of Micrometastatic Cells in the Sentinel Lymph Nodes in Colorectal Cancer
- 94 Downloads
Sentinel lymph node mapping (SLNM) with multilevel sections (MLS) and cytokeratin immunohistochemistry (CK-IHC) of sentinel lymph nodes (SLNs) upstages 15–20% of patients (pts). False-positive SLNs occur in breast cancer due to mechanical transport of cells during mapping procedures, or to pre-existing benign cellular inclusions. Our prospective study evaluated whether colorectal mapping procedures alone caused false positives.
A total of 314 pts underwent SLNM with blue dye. Ninety of the pts underwent a second mapping in normal bowel away from the primary tumor. The first 1–5 blue nodes near the primary tumor were marked as SLNs; those near the second injection site were marked as nontumor SLNs (nt-SLNs). All SLNs and nt-SLNs were evaluated by MLS and CK-IHC.
Of 314 pts, 30 had benign tumor and 284 had invasive cancer. SLNM was successful in 274/284 (96.5%) invasive cancer pts, with 728 SLNs identified. Forty-six of the 274 pts (16.8%) had low-volume metastasis in 57 SLNs: 31 pts (11.3%) had 38 SLNs with micrometastasis (>0.2 mm, ≤2 mm), while 15 pts (5.5%) had 19 SLNs with isolated tumor cells (≤0.2 mm). For 100 pts with second SLNM (70/90 pts successfully mapped with 102 nt-SLNs), or with SLNM of benign pathology (30/30 pts successfully mapped with 88 SLNs), there were no false positives in any of 190 nodes (P < 0.001).
No false positives due to mechanical transport of cells or to benign cellular inclusions were identified in 190 lymph nodes from 100 patients with SLNM in benign bowel.
KeywordsSentinel Lymph Node Methylene Blue Mesothelial Cell Mapping Procedure Isolate Tumor Cell
The authors thank Drs. Julio Badin, Peter Ng, Nader Bassily, Weimin Liu, Ernesto Quiachon, and Aamir Ahsan for their participation in the pathologic evaluation of the cases.
No commercial or other disclosures are reported by the authors of this study.
- 2.Greene F, Page D, Fleming I, Fritz A, Balch C, Haller D, Morrow M. AJCC cancer staging manual, 6th ed. New York: Springer-Verlag; 2002.Google Scholar
- 4.Diaz N, Cox C, Ebert M, Clark J, Vrcel V, Stowell N, et al. Benign mechanical transport of breast epithelial cells to sentinel lymph nodes. Am J Surg Pathol. 2005;28:1641–5.Google Scholar
- 9.Saha S, Dan A, Viehl C, Zuber M, Wiese D. Sentinel lymph node mapping in colon and rectal cancer: its impact on staging, limitations and pitfalls. In: Leong S, Kitagawa Y, Kitajima M, editors. Selective sentinel lymphadenectomy for human solid cancer. New York: Springer-Verlag; 2005. p. 105-22.CrossRefGoogle Scholar
- 13.Bianchi M, Tono L. Contribution to the study of epithelial inclusions of the lymph nodes. Anatomo-clinical considerations on a case of glandular inclusions of the axillary lymph nodes. Arch De Vecchi Anat Patol. 1950, 30:307–19.Google Scholar
- 14.Fragetta F, Vasquez E. Epithelial inclusion in axillary lymph node associated with a breast carcinoma: report of a case with a review of the literature. Pathol Res Pract. 1999;195:263–6.Google Scholar
- 18.Marques B, Gay G, Jozan S, Mirouze A, David J. Embryologic origin of salivary inclusions in the parotid lymph nodes. Bull Assoc Anat (Nancy). 1983;67:219–28.Google Scholar