Head and neck squamous cell carcinoma of unknown primary
- Benjamin E Saltman, MD
Benjamin E Saltman, MD
- Assistant Professor of Otolaryngology
- Division of Head and Neck Surgery
- Hofstra North Shore LIJ School of Medicine
- Sue S Yom, MD, PhD, MAS
Sue S Yom, MD, PhD, MAS
- Associate Professor
- Departments of Radiation
- Oncology and Otolaryngology
- Head and Neck Surgery
- University of California, San Francisco School of Medicine
- Section Editors
- Marshall R Posner, MD
Marshall R Posner, MD
- Section Editor — Cancer of the Head and Neck
- Professor of Gene and Cell Medicine
- The Tisch Cancer Institute
- Icahn School of Medicine at Mount Sinai
- Bruce E Brockstein, MD
Bruce E Brockstein, MD
- Section Editor — Cancer of the Head and Neck
- Clinical Professor of Medicine
- University of Chicago Pritzker School of Medicine
- David M Brizel, MD
David M Brizel, MD
- Section Editor — Radiation Therapy
- Leonard R Prosnitz Professor of Radiation Oncology
- Professor of Otolaryngology Head & Neck Surgery
- Duke University Cancer Institute
- Marvin P Fried, MD, FACS
Marvin P Fried, MD, FACS
- Section Editor — Head and Neck Surgery
- Professor and University Chairman, Department of Otorhinolaryngology - Head and Neck Surgery
- Montefiore Medical Center, Albert Einstein College of Medicine
Head and neck squamous cell carcinoma (SCC) of unknown primary is defined as the presence of SCC in one or more lymph nodes within the head and neck region that are not solely in the supraclavicular region, without an identifiable primary tumor. While many head and neck cancer patients initially present with a neck mass, the mucosally based primary site of origin is usually identified over the course of the subsequent workup.
Thus, SCC of a truly unknown primary origin is a relatively rare entity in the head and neck region; retrospective studies suggest that it represents between 1 and 3 percent of new cases of head and neck SCC . It is commonly thought that many SCC of unknown primary may represent clinically occult oropharyngeal cancers. A contemporary single institution series of 75 patients with SCC of unknown primary found that 69 (90.5 percent) were positive for human papilloma virus (HPV) by either p16 positivity or in situ hybridization , although some older series have reported a lower incidence .
The special case of isolated supraclavicular lymphadenopathy, including those of squamous cell origin, almost always originates from cancer in the skin or a primary site beneath the clavicles (ie, lung, breast, colon, prostate, esophagus, cervix, ureteral, and lymphoma primaries) . These cancers are associated with a different natural history and prognosis than cancers originating from the head and neck.
The management of head and neck SCC of unknown primary is directed at cure for most patients; cervical lymphadenopathy represents disease that is locoregionally advanced but is not distantly metastatic in most patients. This is in sharp distinction to cancers of unknown primary originating from below the clavicles, for which supraclavicular adenopathy may represent incurable distant metastasis.
The diagnosis and management of patients with SCC of unknown primary presumed to originate from the head and neck are presented here. The initial evaluation of a neck mass and the general approach to neoplasms of unknown primary origin are discussed separately.
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- DIAGNOSTIC EVALUATION
- History and examination
- Radiographic imaging
- Staging surgical endoscopy
- Investigational studies
- STAGING SYSTEM
- Primary surgery
- - Postoperative radiation therapy
- Definitive radiation therapy
- Extent of radiation fields
- Radiation dose
- SUMMARY AND RECOMMENDATIONS