Pathology of the N0 neck

The incidence, extent and distribution of nodal metastasis is described in 152 neck dissections from patients with an N0 neck undergoing surgery for an intraoral/oropharyngeal squamous cell carcinoma. The pre-operative N stage had been determined by palpation under general anaesthesia and magnetic resonance imaging. Metastasis was detected histologically in 32 (21%) of the 152 N0 necks. The number of positive nodes per N0 neck ranged from 1 to 6. In total, 52 positive nodes were found and 29 (56%) measured 10 mm or less in maximum dimension. Twenty-one dissections (66%) contained a single positive node and 24 (75%) showed a single positive anatomical level. Three cases showed ‘skipping’ of levels within the neck and one case showed ‘peppering’. Seventeen (53%) of the 32 positive N0 necks and 31 (60%) of the 52 positive nodes contained only ‘micrometastases’ (deposits