Micrometastasis in oral/oropharyngeal squamous cell carcinoma: incidence, histopathological features and clinical implications

The prognostic importance of accurate pathological staging of oral cancer patients with established lymph node metastases is well known. The present study sought to determine the incidence and clinical significance of minimal neck disease (only micrometastases) and to evaluate clinical features of the primary tumour in relation to the pathological metastatic status. Surgical resection specimens from 178 patients with oral/oropharyngeal squamous cell carcinoma were assessed by routine techniques. Micrometastases were defined as intranodal deposits measuring in total no more than 3 mm at any level of sectioning. Fourteen patients (8%) had only micrometastases and 72 (40%) had established nodal metastases. Patients with only micrometastases were younger than those with established metastases, but there were no differences in T site, T stage or sex. The outcome (2–6 years postsurgery) of patients with only micrometastases was similar to those without cervical node metastases. Hence, the main short-term significance of micrometastases seems to be in relation to clinical staging and elective management of the N0 neck.