Sentinel Lymph Nodes Can Give False Positives
Positive results should be interpreted with 'extreme caution,' authors warn
FRIDAY, May 5 (HealthDay News) -- Using sentinel lymph nodes for diagnosis of invasive breast carcinoma may lead to false positive results because of the presence of benign or iatrogenically introduced epithelial cells, according to a report in the May 1 issue of the Journal of Clinical Oncology.
Ira J. Bleiweiss, M.D., from Mount Sinai School of Medicine in New York City, and colleagues reviewed 25 cases of cytokeratin-positive sentinel lymph nodes that contained epithelial cells with different characteristics than the patient's breast carcinoma.
The investigators found that all cases had benign epithelial cells, many matching those of intraductal papillomas that were involved with or separate from the original carcinoma biopsies. Six patients with Her-2/neu-positive ductal carcinoma in situ had sentinel lymph node epithelial cells that were negative and 13 patients with estrogen receptor-positive tumors had estrogen receptor-negative epithelial cells in their sentinel lymph nodes.
Needle biopsy can introduce the epithelial cells into the sample and recent work has shown that benign epithelial cells can be transported to the sentinel lymph nodes, the report indicates. "In the end, the presence of epithelial cells in sentinel lymph nodes must be evaluated carefully on a case-by-case basis with comparative histology and immunohistochemistry until a reliable metastasis specific marker can be developed," the authors conclude.