How do you approach a SCC of unknown primary that is metastatic to a submental (level IA) lymph node?

I would approach both p16 positive and negative cancers the same way for a level IA lymph node. After complete workup including PET/ CT and directed biopsies, if the patient is truly diagnosed as a unknown primary squamous cell ca, I would recommend a neck dissection.

If the patient has had a good neck dissection and this is the only positive node I would keep the patient under close observation with clinical examinations of the oral cavity and 6 monthly CT neck with contrast for the next 2-3 ye...