AAO-HNSF Primary Care Otolaryngology Handbook

CHAPTER 15

the metastases likely to be found in the neck). Many patients present with a mass in the neck, and endoscopy will facilitate identification of the primary tumor. Sometimes the primary tumor is very small, while the neck metastasis is very large. About 10 percent of the time, the primary HNC cannot be identified—this is called “ carcinoma of unknown primary .” Second, endoscopy enables the physician to look for second primaries, which may occur anywhere along the upper aerodigestive tract . And third, physicians use endoscopy to perform a biopsy in order to obtain a tissue diagnosis. This also permits any immunohistochemical staining that can further differentiate the subtype of cancer—e.g., HPV-associated HNC. Otolaryngologists use rigid endoscopes , usually performed under general anesthesia, to perform these biopsies. If the tumor is in the oral cavity, base of the tongue, or oropharynx, it is palpated as well to get a sense of the depth of invasion of the cancer. The procedure usually takes less than an hour and is performed in an outpatient setting. Overnight observation may be necessary if the patient has advanced cancer of the larynx, and there is the potential for airway obstruction and a compromised airway. On occasion, a tracheotomy may need to be performed for definitive airway security until definitive therapy can be completed.

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One proviso: In the modern evaluation and treatment planning of head and neck cancers, diagnostic imaging (e.g., CT, magnetic reso- nance imaging, PET, ultrasound), in-office endoscopy, and the use of FNAB may obviate the need for endoscopy under anesthesia in selected situations. In many cases diagnostic imaging is conducted because it provides important information about the depth and extent of the tumor that cannot otherwise be appreciated (Figure 15.3). Diagnosis and Treatment Remember that endoscopy is used to evaluate the size of the tumor, including estimation of the third dimension (depth). In general, T1 cancers are smaller than 2 cm, T2 are 2–4 cm, T3 are larger than 4 cm, and T4 are large, invasive

Figure 15.3. Mass occurring in mid-portion of right neck in a man with a past history of tobacco use. This most likely represents metastatic squamous cell cancer from a primary site somewhere in the upper aerodigestive tract. Diagnostic workup includes head and neck examination, CT scan imaging, and fine-needle aspiration biopsy.

Primary Care Otolaryngology