Fine-needle aspiration cytology of the sentinel lymph node in head and neck cancer.

UNLABELLED In squamous cell carcinoma of the head and neck, staging of the neck cannot rule out occult metastatic disease. An improved staging is necessary to avoid elective neck dissection in patients staged as N0. The study was performed to determine the feasibility of the detection of occult metastatic disease by ultrasound-guided fine-needle aspiration cytology (USgFNAC) of sentinel lymph nodes (SLN). METHODS Sixteen consecutive patients diagnosed with oral, oropharyngeal, or dermal squamous cell carcinoma who had been staged as N0 underwent lymphoscintigraphy in double tracer technique to localize SLNs. A USgFNAC was performed on SLNs before elective neck dissection. The results of USgFNAC were compared with pathohistologic findings, which were regarded as the gold standard. RESULTS Seven of 16 patients were upstaged to N+ after histopathologic examination of the neck dissection specimen. In only 1 of these patients was metastatic disease detected by USgFNAC of the SLN. CONCLUSION The combination of lymphoscintigraphy and USgFNAC of the SLN improves preselection of N+ patients and, thus, the staging procedures. However, based on present results this method does not seem reliable in deciding whether an elective neck dissection can be avoided. A biopsy of the SLN with close histopathologic work-up seems to be mandatory for the detection of occult metastatic disease, because the merely incidental aspiration of micrometastatic material within normal-sized lymph nodes results in a high number of false-negative results by USgFNAC.