What head and neck subsites would you treat for a SCC of multiple ipsilateral neck nodes (clinical ECE, no contralateral nodes) with unknown primary origin site despite full workup?  

Oropharynx, bilateral neck, ipsilateral RP nodes, and nasopharynx. You could omit the NPX but you’re up there anyway to treat the RPs.

With such bulk in the neck, the contralateral neck and ipsilateral RP nodes should be treated. Regarding mucosal coverage, recent ASCO guidelines suggest the ipsilateral oropharynx can be treated alone regardless of p16. However, as @William M. Mendenhall said, with the RPs being so close, cove...

For me, the answer depends on P16 status and nodal location(s). If P16+ and level II-V, I would presume it is a pharyngeal primary and treat the pharyngeal axis including the nasopharynx, oropharynx, and ipsilateral pharyngeal wall. I typically include the nasopharynx because a reasonable number of ...

The ASCO Consensus Guidelines referenced by @Matthew C. Ward are a great resource. If the primary site remains occult after a comprehensive work-up, clinicopathologic features can guide mucosal and contralateral neck coverage. If pathology (ISH for EBV or HPV) or history (prior H&N NMSCs) sugges...

I agree with my colleagues' posts and would offer a few general comments on the subject, as well as some specific to the case presented.  As noted by others, several factors must be taken into account and there is no "one-size-fits-all" recommendation for H&N SCCUP, though the ASCO guideli...

Agree with Dr. Mendenhall with regards to managing p16 negative disease (stage IVB). I would give chemo+RT (Ipsilateral oropharynx, possibly ipsilateral hypopharynx, bilateral necks, bilateral RP nodes). Management of p16+ (stage I) would, however, have to be more nuanced based on age, PS, smoking h...