Familial Nasopharyngeal Carcinoma 6

44 S. S. Lo and J. J. LuFig. 4.1. This was a patient diagnosed with NPC who presentedwith dermatomyositis; his rash improved after treatmentwith steroid. (Courtesy of Department of ClinicalOncology, Queen Elizabeth Hospital, Hong Kong)uncommon to see patients with NPC presenting withsymptoms related to distant metastases. In moststudies, approximately 1–5% of the patients have distantmetastasis at the time of first presentation (Leeet al. 1992; Lee and Fu 2004; Skinner et al. 1991;Stanley and Fong 1997). Bone, specifically the thoracolumbarspine, is the most common site of metastasis(Stanley and Fong 1997). Other sites includelung and liver. The presenting symptoms depend onthe site and extent of the metastatic lesions.4.4Neurological SyndromesA few syndromes associated with neurologic deficitscaused by NPC have been described (Lee and Fu2004):1. Petrosphenoidal syndrome of Jacod – This is aresult of direct intracranial extension of the NPCwith involvement of the II to the VI nerves. This willcause unilateral trigeminal type neuralgia, unilateralptosis (caused by III nerve involvement), completeophthalmoplegia (caused by involvement ofthe III, IV, and VI nerves), and amaurosis (caused byinvolvement of the optic nerve).2. The syndrome of the retroparotid space of Villaret– This is a result of the involvement of the last fourcranial nerves and cervical sympathetic nervecaused by lateral retropharyngeal lymph nodemetastasis in the retroparotid space. Patients presentingwith this syndrome will have difficulty inswallowing (as a result of the involvement of theIX and X nerves), perversion of taste in the posterior1/3 of the tongue (caused by involvementof the IX nerve), hyperesthesia, hypoesthesia, oranesthesia of the mucous membranes of the softpalate, pharynx, and larynx, and problems withrespiration and salivation (caused by the involvementof the X nerve), paralysis and atrophy of thetrapezius and sternocleidomastoid muscles andunilateral weakness of the soft palate (caused bythe involvement of the XI nerve), and unilateralparalysis and atrophy of the tongue (caused by theinvolvement of the XII nerve). When the cervicalsympathetic nerves are also involved, the patientmay present with Horner’s syndrome.3. Trotter’s syndrome – This is a clinical trait of unilateraldeafness, neuralgia affecting the branches ofthe trigeminal nerve, and defective mobility of thesoft palate as a result of the NPC involving the fossaof Rosenmüller. It can masquerade as dental masticatorypain. Trismus may also occur as a result ofinvolvement of the medial pterygoid muscle.4.5Routes of Tumor SpreadAs radiation therapy is the mainstay of treatmentfor NPC, accurate target delineation is of utmostimportance. To facilitate proper target delineation,the knowledge of the anatomy of the nasopharynxand the patterns of spread of NPC is crucial.4.5.1Clinical Anatomy and Lymphatic DrainageThe nasopharynx is a space without many naturalbarriers to spread of tumor growth, but with manycritical structures in the immediate vicinity. It islocated below the base of skull and behind the nasalcavity. The nasopharynx is in continuity with thenasal cavity near the posterior choanae. The first twocervical vertebral bodies constitute the posteriorwall. The basisphenoid, basiocciput, and the anterior