Salvage neck dissections in oral and oropharyngeal squamous cell carcinoma: histological features in relation to disease category.

The histological findings in a series of 37 salvage neck dissections from patients who had an oral or oropharyngeal squamous cell carcinoma managed initially by primary surgery with or without neck dissection, and without postoperative radiotherapy, are described. None of the cases had an intraoral relapse. Pathological stage N2 or N3 disease was seen in 87% of the 15 salvage dissections from 'wait and watch' necks, 100% of the 10 salvage dissections of contralateral necks and 50% of the 12 salvage dissections of operated necks. The typical 'inverted-cone' pattern of metastasis was seen in 87% of 'wait and watch' necks. Skip or non-contiguous metastases to level III/IV accounted for relapse in 30% of the contralateral and 66% of the operated necks. The median time interval between original surgery and the salvage neck dissection was 15 months (range 1-48 months). In at least 15% of cases, the short time interval coupled with the histopathological features suggested that the metastatic disease suddenly became more rapidly progressive following removal of the primary tumour.