Tongue base mucosectomy identified cancer in 78 per cent of cancers of unknown primary in a recent meta-analysis. The carbon dioxide laser is an alternative technique if there is no access to a robot. This study aimed to describe the steps for undertaking tongue base mucosectomy using the carbon dioxide laser and its diagnostic utility in cancers of unknown primary.

This was a prospective feasibility study utilising carbon dioxide laser for tongue base mucosectomy in cancers of unknown primary. Data collected included demographic data and p16 status.

There were 14 cancers of unknown primary with 86 per cent p16 positivity on immunohistochemistry. Laser tongue base mucosectomy alone identified the cancer primary in 7 of 12 (58 per cent) cancers of unknown primary among p16 positive tumours and 0 of 2 (0 per cent) among p16 negative tumours. Combining bilateral tonsillectomy with laser tongue base mucosectomy resulted in identification of the primary cancer in 8 of 12 (67 per cent) p16 positive tumours.

In centres without a robot, tongue base mucosectomy using the carbon dioxide laser is a viable alternative, especially in combination with bilateral tonsillectomy in p16 positive cases.