title: A new paradigm for the diagnosis and management of unknown primary tumors of the head and neck: a role for transoral robotic surgery.
abstract: OBJECTIVE
  In 2% to 3% of patients with cancer metastatic to cervical lymph nodes, a primary tumor will not be found despite exhaustive diagnostic efforts. The treatment for these patients includes cervical lymphadenectomy followed by radiation to areas with increased risk of harboring a mucosal primary. Wide-field radiation therapy increases the incidence of xerostomia and dysphagia. Localizing a primary tumor has thus both therapeutic and quality-of-life implications, allowing possible complete surgical excision, concentrated radiation therapy, and potential deintensification of adjuvant therapy. With improved visualization and freedom of motion, transoral robotic surgery (TORS) is an innovative surgical modality that allows resection of oropharyngeal subsites with minimal morbidity.
  
  
  METHODS
  Retrospective chart review.
  
  
  METHODS
  Ten patients with unknown primary tumors of the head and neck were identified. All patients underwent a cervical biopsy, positron-emission tomography/computed tomography, formal endoscopy, and bilateral tonsillectomy. When the initial endoscopy and biopsies did not localize a primary tumor, all patients underwent transoral robotic base of tongue resection.
  
  
  RESULTS
  Evaluation of the patients' oropharyngeal mucosa using the robot did not reveal an obvious lesion and no palpable tumors were appreciated in the resected specimens. In 9/10 (90%) patients, pathologic examination revealed invasive squamous cell carcinoma (SCCA) with a mean diameter of 0.9 cm.
  
  
  CONCLUSIONS
  Unknown primary SCCA presents a diagnostic challenge to the head and neck surgeon. We present a small series of tumors that would have been treated as unknown primaries under traditional diagnostic and therapeutic algorithms. TORS base of tongue resection identified primary tumors in 90% patients with minimal morbidity.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of Pittsburgh Medical Center, Eye and Ear Institute, Pittsburgh, PA 15213, USA.
authors.forename: Vikas
authors.initials: V
authors.lastname: Mehta
authors.forename: Paul
authors.initials: P
authors.lastname: Johnson
authors.forename: Andrew
authors.initials: A
authors.lastname: Tassler
authors.forename: Seungwon
authors.initials: S
authors.lastname: Kim
authors.forename: Robert L
authors.initials: RL
authors.lastname: Ferris
authors.forename: Melonie
authors.initials: M
authors.lastname: Nance
authors.forename: Jonas T
authors.initials: JT
authors.lastname: Johnson
authors.forename: Umamaheswar
authors.initials: U
authors.lastname: Duvvuri
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D012371:Robotics / Q000379:methods*; D014057:Tomography, X-Ray Computed; D014059:Tongue / Q000601:surgery*