The topography of cervical lymph node metastases revisited: the histological findings in 526 sides of neck dissection from 439 previously untreated patients.

The pathological reports, minimum datasets and topographical plots of the neck dissections from 439 cases of oral and oropharyngeal cancer reported by a single pathologist following a standard protocol were analysed. Metastasis was evident in 47% of patients including bilateral metastases in 6%, extracapsular spread in 29% and matting in 7%. The extent of metastasis (both volume and distribution) was greatest in tumours of the oropharynx followed by lateral tongue, ventral tongue and floor of mouth. The typical 'inverted-cone pattern' was seen in 67% of patients with metastasis. A single micrometastasis was seen in 14%, skip lesions in 10% and involvement of 'other' nodal groups in 4%. Contralateral neck metastases (0.4%), peppering (2%), flushing of lymph node sinuses (1%) and all nodes positive (0.4%) accounted for the remaining 'aberrant' patterns. Skip lesions were seen in tumours at all sites other than retromolar.