Lingual Tonsillectomy Likely Does Not Improve Outcomes for Squamous Cell Carcinoma of the Head and Neck From an Unknown Primary Site. 
Patients with mucosal squamous cell carcinoma (SCC) of the head and neck almost always have a primary site in the base of tongue or tonsillar fossa.  Lingual tonsillectomy has recently been advocated as part of the diagnostic evaluation as opposed to directed biopsies of the base of tongue and thought to possibly result in an increased likelihood or cure.  The purpose of this project is to determine whether this is probable.  We reviewed the medical records of patients treated with primary radiotherapy (RT) between January 1983 and March 2013.  The outcomes were compared following RT in consecutively treated patients with either T1-2 base of tongue or unknown primary (cancer of unknown primary) SCC with predominantly level 2 adenopathy.  At 10 years, there were no clinically significant differences in the 2 groups, in local control, regional control, freedom from distant metastases, disease-specific, or cause-specific survival.  Overall survival at 10 years was improved with T1-2 base of tongue cancers but not for those with T0 N3 disease.  The reasons for this are unclear.  Tongue base biopsy (or lingual tonsillectomy) likely increases the probability of identifying an unknown primary in the base of tongue, but it does not improve outcome following RT for patients with cancer of unknown primary SCC with predominantly level 2 adenopathy.