MICROMETASTASES IN CARCINOMA OF THE UPPER AERODIGESTIVE TRACT - DETECTION, RISK OF METASTASIZING, AND PROGNOSTIC VALUE OF DEPTH OF INVASION

Background. The purpose of this study was to investigate the incidence of micrometastases from squamous cell carcinomas of the upper aerodig estive tract in neck dissection specimens, and to determine whether fe atures of the primary tumor might be of prognostic value for metastasi zing. Methods. Seventy-six originally pNO staged neck dissection speci mens from 60 patients were evaluated using serial sectioning in 10-mu m intervals, H&E-staining and immunostaining with an antibody to pan-c ytokeratin. The influence of the variables pT-category, cytologic grad e, and maximum depth of invasion of the primary tumor on the nodal sta tus was analyzed in 128 patients. Results. The examination of 1020 lym ph nodes from 76 neck dissection specimens revealed 8 micrometastases in 6 specimens (7.9%) from 6 patients with oral and pharyngeal primari es, resulting in upstaging. Six micrometastases were located in lymph nodes of 3-6 mm in diameter. Depth of invasion was the only significan t risk factor for metastasizing selected in logistic regression. Concl usion. The surgeon should be aware of a relatively high incidence of m icrometastases from oral and pharyngeal carcinomas, which are neither detectable preoperatively nor histopathologically by a reasonable effo rt. The measurement of the maximum depth of invasion of the primary ca n delineate a group of patients who should be treated by elective neck dissection. (C) 1995 John Wiley & Sons, Inc.