Cianchetti 2009 (Occult Primary Workup)

Background

Retrospective, single-institution analysis (University of Florida). N=236 patients evaluated June 1983–December 2008 for squamous cell carcinoma metastatic to cervical lymph nodes from an unknown primary head and neck site. Evaluated optimal diagnostic workup including cross-sectional imaging, PET/CT, and bilateral tonsillectomy to identify the occult primary.

Interventions and follow up

Design: Comprehensive review of workup strategies (imaging, panendoscopy, ipsilateral/bilateral tonsillectomy, transoral surgery) for SCC of unknown primary presenting in cervical nodes
Primary endpoint: Diagnostic yield by modality
mFollow up: Not applicable

Results

Primary site identified: 126/236 (53.4%); two patients had two synchronous primaries
Most common primary sites: tonsillar fossa 59 (44.7%); base of tongue 58 (43.9%)
Tonsillectomy yield: primary found in 35/79 (44.3%)
PET/FDG as sole detection method: only 1/47 (2.1%)

Adverse events

Procedure-related morbidity: tonsillectomy complications, endoscopy risks
Overall: low procedure-related morbidity

Conclusions

The most common occult primary sites are the tonsillar fossa and base of tongue (combined 88.6% of identified primaries). Tonsillectomy identified the primary in 44% of patients who had the procedure. FDG-PET was rarely the sole detection method (2.1%). Physical exam, CT/MRI, and panendoscopy with tonsillectomy remain the cornerstone of evaluation.

Key Limitations

Retrospective, single-institution over a 25-year span with evolving imaging technology; selection and referral bias. Predates routine HPV/p16 and transoral robotic surgery; no central pathology review.

Clinical Context

Supports ASCO/ESMO-aligned workup of cervical nodal SCC of unknown primary: thorough exam, cross-sectional imaging, PET/CT, panendoscopy, and tonsillectomy (including base-of-tongue mucosectomy in the HPV era).

References