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The most frequent malignant head and neck neoplasms can be grouped under two major headings. The most abundant are the epithelial malignancies of the mucous membranes of the upper aerodigestive tract, so-called head and neck squamous cell carcinoma (HNSCC), accounting for about 90% of all head and neck neoplasms ( et al. 2001). The second largest group of neoplasms can be described as “glandular neoplasms”, the majority arising in the thyroid, a minority in the salivary glands.

Head and neck neoplasms present with variable signs and symptoms, depending on their site of origin and extension pattern. Thorough clinical examination, aided by modern endoscopic devices, is a cornerstone of the pre- and posttherapeutic evaluation of the patient suffering head and neck cancer. This chapter reviews the possibilities, but also the limitations of the clinical examination for each of the major subsites in the head and neck region.

Various imaging techniques are used in the evaluation of patients with head and neck cancer, before, during and after treatment. Each of these imaging techniques has its own advantages and disadvantages.

The larynx is one of the most frequent head and neck cancer sites. Nearly all laryngeal malignancies are squamous cell carcinomas. Cigarette smoking and excessive alcohol consumption are well-known risk factors. An important factor in the treatment planning of laryngeal neoplasms is the accuracy of pretherapeutic staging. As most laryngeal tumors are mucosal lesions, they can often be seen directly or indirectly, but the limitations of clinical and endoscopic tumor evaluation are well recognized. The clinical and radiological evaluation of laryngeal tumors are complementary; the combination of the obtained information will lead to the most accurate determination of tumor extent. Imaging may be used to monitor tumor response and to detect recurrent or persistent disease as early as possible.

Cancers of the hypopharynx and proximal esophagus represent one of the most difficult diseases for head and neck surgeons to manage as they pose a significant diagnostic challenge. The trend of these cancers to grow in submucosal fashion, combined with the complex functions of the hypopharynx, esophagus and adjacent larynx, requires detailed mapping of the tumor boundaries to yield the most optimal treatment selection, determine the extent of possible surgical resection and subsequent reconstructive surgery. Consequently, cross-sectional imaging plays a critical role in evaluation of hypopharyngeal and esophageal cancers.

Predominantly, oral cavity lesions are clinically apparent. Except for important information on the differential diagnosis, cross-sectional imaging provides the clinician with the crucial pretherapeutic information on deep tumor infi ltration. In this regard, the clinician needs to know exactly which anatomic structures (Figs. 6.1–6.6) are involved.

Head and neck cancer commonly originates from the oropharynx. As in most head and neck sites, squamous cell cancer is the most frequently encountered malignant disease. Cigarette smoking and excessive alcohol consumption are well-known risk factors. The accuracy of pretherapeutic staging is an important factor in the treatment planning of oropharyngeal neoplasms; clinical examination and imaging studies are complementary in precisely evaluating tumor extent. As an adjunct to clinical surveillance, imaging can be used to monitor tumor response and to detect recurrent or persistent disease as early as possible.

The nasopharyngeal mucosa consists of epithelium that is largely squamous in adult life, with foci of pseudostratifi ed respiratory type surface epithelium, lymphoid submucosal stroma and seromucinous glands. A wide variety of malignant neoplasms can theoretically originate from the nasopharyngeal mucosa but regardless of geographic distribution, undifferentiated carcinoma is the most common form of malignancy, accounting for up to 98% of all nasopharyngeal malignancies in the Orient ( et al. 1979). Nasopharyngeal carcinoma (NPC) is a unique malignancy, representing the outcome of interactions of genetic factors, environmental factors and the Epstein-Barr virus (EBV). Patients with NPC show consistently high levels of antibodies to EBV antigens and these antibodies are very useful diagnostic markers.

The parapharyngeal space (PPS) is a deep space of the neck shaped as a tilted up pyramid with its base attaching to the skull base and the apex reaching the level of the hyoid bone, and almost exclusively containing fat. Primary neoplasms arising in this space are quite rare, accounting for only 0.5% of all head and neck tumors ( 1994; et al. 1996; et al. 2002), whereas the PPS is more commonly displaced or infiltrated by lesions arising in the adjacent spaces, including the pharyngeal mucosal, masticator, parotid, and retropharyngeal spaces. Approximately 70%–80% of the tumors originating from the PPS itself are benign (- et al. 2005).

The masticator space (MS) is a deep facial space delineated by a splitting of the deep cervical fascia which encloses the four muscles of mastication: the medial and the lateral pterygoid, the masseter, and the temporalis muscles – hence the denomination of “masticator space” ( 1995; and 2004). The MS also contains the ramus and posterior body of the mandible and the third division of the fi fth cranial nerve (mandibular trigeminal branch or V3). The V3 nerve gives motor innervation to the mastication muscles and relays sensory information from the inferior teeth, gums and lower lip/chin region through the inferior alveolar nerve. The nerve emerges from the endocranium to the MS through the foramen ovale. The space is easy to identify on both CT and MR images (Figs. 10.1, 10.2) because of easily recognizable shape and location of the mastication muscles ( and 1991; and 1998). The inferior limit of the MS is the attachment of the medial pterygoid muscle to the mandible. The space has two distinct superior margins. The base of the skull is the superior limit of the “infratemporal fossa” or “nasopharyngeal masticator space” which encompasses all soft tissue below the foramen ovale. The second superior margin is the attachment of the temporalis muscle to the outer table of the skull; this part is called the “temporal fossa”, or the “suprazygomatic masticator space” because it is above the zygomatic arch (Fig. 10.2). The MS is separated from the parapharyngeal space by a fascial layer extending from the medial pterygoid muscle to the skull ( 1987). The fascia is also attached to the anterior aspect of the mandibular ramus, has an interface with the oral cavity, and reaches the posterior margin of the ramus, where the masticator space constitutes the anterior border of the parotid space.