Pathological findings in clinically false-negative and false-positive neck dissections for oral carcinoma.

A series of 86 patients presenting with oral cancer underwent neck dissection (114 sides of neck), after preoperative staging by palpation under general anaesthesia and CT imaging. Detailed histopathological assessment of the surgical neck dissection specimens showed the incidence of clinically false-negative and false-positive assessments was 27% and 40%, respectively. Extranodal spread of metastatic carcinoma was present in 16% of clinically negative necks. The pathological findings provided plausible explanations for the clinical misdiagnosis in all 19 of the false-positive necks and in 13 of the 18 false-negative necks, where micrometastases or metastasis to nodes measuring less than 1.7 cm accounted for five and seven misdiagnosed cases, respectively. We conclude that the most stringent clinical protocols, even when supplemented by CT scanning, cannot be expected to achieve 100% accuracy. Detailed histopathological assessment provides the most reliable, currently available method of diagnosing cervical metastatic disease.