Sentinel lymph nodes in cancer of the oral cavity: isolated tumour cells

BACKGROUND: Sentinel lymph node biopsy, step sectioning and immunohistochemistry have changed detection of tumour deposits. Isolated tumour cells (ITC) are detected more frequently than earlier because of a changed level of detection.

METHODS: A total of 108 sentinel lymph nodes from 30 patients with T1/T2 cN0 oral cancer were re-classified histologically to find possible ITC and to describe technical pitfalls.

RESULTS: Primarily we found metastatic spread in 12 of 108 sentinel lymph nodes: five macrometastasis and seven micrometastasis. After re-classification, we found seven lymph nodes with macrometastasis, five with micrometastasis and two with ITC.

CONCLUSION: The ITC are probably precursors of micrometastasis waiting to grow and should be treated as such. Benign inclusions and dendritic cells did not cause problems, but can mimic ITC.