Purpose of review: To look at the current published literature on squamous-cell carcinoma of the head and neck, at the microscopic level, and the implications of molecular and genetic research.
Recent findings: The goal of surgical treatment is still complete eradication of the primary tumour with a 'safe margin'. To achieve this 'safe margin' is not always possible, however. Currently, there is no agreed consensus as to how to submit tissue for frozen section, or how to define a 'clear margin'. Histopathologically, there are two margins requiring analysis, the mucosal margin and the 'deep margin'. Margins declared histopathologically 'tumour free' can be found to be positive for malignant/premalignant cells when molecular markers are applied. When the presence of genetically altered cells is suggested in the margins, there is an increased risk of a recurrent or new tumour. There is limited application of such knowledge and further trials are awaited.
Summary: Standard histopathology has limitations for examining surgical margins. The probability of recurrent malignant disease is explained and this is much increased when molecular markers are identified in the resected margins. Further studies are required.