Histological distribution of cervical lymph node metastases from intraoral/oropharyngeal squamous cell carcinomas.

The histological frequency and distribution of cervical lymph node metastases was studied in 326 neck dissections from 253 patients with an intraoral/oropharyngeal squamous cell carcinoma. Metastasis was evident in 118 patients (47%) and 18 had bilateral metastasis. For primary sites other than the tongue, metastasis developed initially in a node(s) in the first drainage group (level I or II) with progressive involvement of neighbouring nodes ('overflow'). Simultaneous bilateral metastases were seen in some tumours of the floor of mouth, tongue and oropharynx which involved the midline. An erratic distribution of metastases suggestive of 'fast-tracking' (skip lesions and peppering) was only seen in tongue tumours. The pattern of metastatic spread indicates that level IV nodes must be included in staging and therapeutic neck dissections in tongue cancer. Metastasis to 'accessory' lymph nodes (lingual, buccal) occurs infrequently but may explain some 'local' recurrences.