The Laryngoscope V C 2011 The American Laryngological, Rhinological and Otological Society, Inc. Transoral Laser Microsurgery: A New Approach for Unknown Primaries of the Head and Neck Ron J. Karni, MD; Jason T. Rich, MD; Parul Sinha, MBBS, MS; Bruce H. Haughey, MBChB, FACS, FRACS Objectives/Hypothesis: To evaluate the efficacy of transoral laser microsurgery (TLM) used at examination under anes- thesia (EUA) for detection and management of an unidentified primary site and to determine survival with both TLM EUA and traditional rigid pharyngolaryngoscopy EUA, with directed biopsies. Study Design: Comparative retrospective review of patients who underwent two different procedures, TLM EUA and traditional EUA, to identify a primary site. Methods: Thirty patients presenting with occult primary met the study criteria. Eighteen underwent TLM EUA and 12 underwent traditional EUA. We collected data on the treatment approach, detection rate of the primary site, neck dissection, postoperative radiotherapy, and disease-free survival (DFS). Results: The primary site detection rate with TLM EUA was 94% (17 of 18) and with traditional EUA was 25% (3 of 12). Overall, the occult primary was identified in 20 of 30 patients. The majority of patients (95%) had a primary in the oro- pharynx (19 of 20). Sixteen occult primaries in the TLM EUA group were immediately resected with TLM. At median follow- up of 30 months, there was no recurrence in the TLM EUA group. There was a 41.6% (5 of 12) recurrence rate in traditional EUA group. The Kaplan-Meier 5-year DFS was 100% for the TLM EUA group and 44% for the traditional EUA group (log rank value ¼ 0.0006). Conclusions: TLM management of occult primary malignancies allowed high detection rates of primary tumor and was associated with a high level of DFS. Application of TLM during EUA both detects and treats the primary and may decrease the number of patients requiring wide-field irradiation. Key Words: Occult primary tumor, unknown, transoral laser microsurgery, cervical metastases, squamous cell carcinoma, head and neck neoplasms. Level of Evidence: 2b. Laryngoscope, 121:1194–1201, 2011 INTRODUCTION Metastatic cervical lymphadenopathy is a common presentation of squamous cell carcinoma of the head and neck, especially from primary tumors of the oropharynx. In these patients, initial management is directed toward the identification of a primary lesion. A thorough head and neck examination including palpation, flexible lar- yngoscopy plus imaging using computed tomography (CT), magnetic resonance imaging (MRI), positron emis- sion tomography (PET) or PET/CT is often performed. If these do not reveal the primary, then operative phar- yngolaryngoscopy and directed biopsies are usually performed. For the latter, the patient is brought to the operating room for an examination under anesthesia (EUA) of the upper aerodigestive tract, which is followed by biopsies of possible primary sources, typically naso-, oro-, and hypopharyngeal sites and any other areas that raise a suspicion of malignancy. Special scrutiny is given to those areas that present a likely mucosal watershed to the region or level of the malignant lymph node. How- ever, traditional EUA with rigid pharyngolaryngoscopy, tonsillectomy, and directed biopsies results in identifica- tion of a primary lesion in only 17% to 40% of patients, even when excisional biopsies are performed. 1 Further- more, despite a wide variety of treatment protocols among established cancer institutions, the reported 5- year overall survival of patients with cervical squamous cell carcinoma from an unknown primary site is approxi- mately 50%. 2–5 Several authors have shown that the identification of an occult lesion during EUA may significantly improve the long-term survival of patients with this dis- ease entity. 1,3,5 Also of benefit to patients, the identification of an occult lesion can obviate wide-field mucosal irradiation of all potential primary sites in the head and neck. 2 From the Department of Otolaryngology–Head and Neck Surgery, University of Texas, Houston, Texas (R.J.K.), U.S.A; and Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri (J.T.R., P .S., B.H.H.), U.S.A.. Editor’s Note: This Manuscript was accepted for publication Janu- ary 4, 2011. Study performed at Washington University School of Medicine, St. Louis, Missouri, U.S.A. This material was a poster tour presentation at the American Head and Neck Society Annual Meeting and Research Workshop on the Biology, Prevention and Treatment of Head and Neck Cancer, August 17–20, 2006, Chicago, Illinois, U.S.A. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Bruce H. Haughey, MBChB, FACS, FRACS, Kimbrough Professor and Director of Head and Neck Surgical Oncology, Department of Otolaryngology–Head and Neck Surgery, Wash- ington University in St. Louis School of Medicine, 660 S. Euclid Ave, Campus Box 8115, St. Louis, MO 63110. E-mail: haugheyb@ent.wustl. edu DOI: 10.1002/lary.21743 Laryngoscope 121: June 2011 Karni et al.: TLM for Occult Primary Malignancy 1194