- Primary neoplasms of the soft tissue in the head and neck are rare.
- The most common benign tumors are paragangliomas and nerve cell tumors.
- The most common malignant neoplasm is metastatic squamous cell carcinoma from the upper aerodigestive tract.
- The evaluation of a metastatic squamous cell carcinoma without an easily identifiable primary site is extensive and treatment is controversial.
- Neck dissections are performed to treat metastatic neoplasms and to determine the presence of occult metastasis.
Neck neoplasms include not only metastatic squamous cell carcinoma but also a number of other primary neck tumors. Metastatic squamous cell carcinoma arises from the upper aerodigestive tract and is present in the lymph nodes and in the neck; other primary tumors arise from the soft tissue in the neck, such as fat, fibrous tissue, muscle, blood vessels, lymphatic vessels, nerves, and paraganglia (Table 28–1). These primary tumors are fairly uncommon, often making a pathologic diagnosis difficult. The evaluation of all neck masses consists of obtaining a complete history and conducting a physical exam.
Table 28–1. Differential Diagnosis of Benign and Malignant Neck Neoplasms. |Favorite Table|Download (.pdf)
Table 28–1. Differential Diagnosis of Benign and Malignant Neck Neoplasms.
|Paraganglioma—glomus vagale, carotid body tumor||Synovial sarcomas|
|Neural—Schwannoma, neurofibroma||Malignant peripheral nerve sheath tumor|
The presenting symptom of a neck neoplasm is a painless enlarging neck mass that may grow extremely slowly or very rapidly. On physical examination, there is often a well-circumscribed mass in the neck. The location of the mass sometimes suggests its cause.
Imaging with computed tomography (CT) or magnetic resonance imaging (MRI) is critical for these lesions, especially if these studies are performed before a biopsy is obtained. A preoperative study can better assess both the size and the extent of the lesion without confounding factors such as bleeding and edema. An MRI is often the study of choice because it allows a greater differentiation of soft tissue. A positron emission tomography (PET) scan in evaluating patients with metastatic disease can identify additional tumor masses. Additional studies such as angiography and, recently, magnetic resonance angiography (MRA) add valuable information to the diagnosis of vascular lesions (eg, carotid body tumors and vascular malformations).
Fine-Needle Aspiration (FNA) Biopsy
A tissue specimen is vital for the diagnosis of neck neoplasms and can be obtained via a fine-needle aspiration biopsy (FNAB). Metastatic squamous cell carcinoma has an excellent specificity and sensitivity for FNAB. Additional studies such as flow studies, immunohistochemistry techniques, or electron microscopy may be required for an accurate diagnosis of these specimens.