Pathology of the Head and Neck

Neck Cysts, Metastasis, Dissection Chapter 9 273composed of tumours that are usually smaller and morelikely to be malignant [9, 33, 44, 50].Various systems of classification for teratomas havebeen proposed. The majority of these were consideredby Gonzalez-Crussi, who presented a tentative new classificationsystem for all teratomas that does not rely onthe primary site of occurrence of the tumour [44].On gross examination, these tumours are usuallycystic, but they can be solid or multiloculated. They arecommonly encapsulated, lobulated masses that measureup to 15 cm in their greatest dimension [44]. On microscopicexamination, the cervical teratomas are similar tothose found in other anatomical regions. They may containskin, hair, fatty tissue, central nervous tissue, cartilage,bone and components of the respiratory or digestivetract (Fig. 9.10). Areas of more immature or embryonaltissue may be present (Fig. 9.11).It is exceedingly important to adequately sampleall potentially teratomatous tumours. Specifically, solidareas with necrosis or haemorrhage should be carefullyexamined. It is not unusual to find, in teratomasthroughout the body, small foci of malignant germ celltumours, especially endodermal sinus tumour or choriocarcinoma.The presence of either of these two tissuetypes adversely affects patient prognosis. It is also importantfor the pathologist to recognise that the moreimmature foetal tissues have malignant potential [10, 33,44, 50]. Patients with these tumours require especiallyclose clinical follow-up.Cervical teratomas in the neonate are almost alwaysbenign, whereas the few reported cases of cervical teratomaarising in adults were malignant [44]. To the bestof our knowledge, only seven cases of congenital cervicalteratoma with metastasis have been reported [50].Resection seems to offer the best control in cases of aggressivebiologic behaviour.Most authors strongly favour the operative managementof teratomas [33, 44, 50]. When malignant componentsare found in a teratoma, the patient may need chemotherapyand/or radiotherapy in addition to surgery.9.4.4 Cervical SalivaryGland Cystic NeoplasmsHeterotopic normal salivary glands and salivary glandneoplasms arising in cervical lymph nodes may simulatecervical cysts [107, 131]. These are uncommon neoplasms,and the pathologist may confuse them with metastaticsalivary gland tumours [23, 131]. Ectopic islands of salivarygland tissue within lymph nodes have been implicatedin the pathogenesis of lymphoepithelial cysts andsome neoplastic lesions by several authors [22, 108].This type of neoplasm presents as a painless mass,often cystic, located in the periparotid region, the upperneck, or the anterior cervical triangle. Occasionally,however, these tumours have been described in thelower neck [108, 131]. In the series reported by Zatchuzet al., the age of the patients ranged from 10 to 81 years,with a mean of 45 years. Females were affected morecommonly than males, with a ratio of 3:1 [131].The tumours that more often arise in ectopic salivarygland tissue in the lymph nodes and simulate cysts areWarthin’s tumour and sebaceous lymphadenoma. Otherrare types of salivary gland tumours that may resemblecervical cysts, are dermal analogue tumours, mucoepidermoidcarcinomas and acinic cell carcinomas [67, 103].The pathology of these lesions is discussed in Chap. 5.Surgical excision is the treatment of choice. In sialocarcinomas,excision of the adjacent salivary gland mayappear to be the appropriate treatment to define the siteof the primary tumour, because malignant salivary tumourslocated within lymph nodes suggest metastaticdisease.9.4.5 Miscellaneous LesionsOther tumours that may appear as cervical cysts arecystic neurogenic neoplasms and cervical thymomas.In the neck, the most common locations for neuromaswith cystic degeneration are along the course of the vagusnerve or the cervical sympathetic chain [4]. Cervicalthymomas are classified as being one of four types:1. Ectopic hamartomatous thymoma,2. Cervical thymoma,3. Spindle epithelial tumour with thymus-like differentiation(SETTLE),4. Carcinoma showing thymus-like differentiation(CASTLE).Of these, the first is benign and the second can be locallyaggressive. The third and fourth types are malignant[18].Infectious processes often simulate cervical cysts.Such infections can be bacterial, fungal, parasitic, or viral[46, 104, 114]. Amyloidosis and carotid artery aneurysmshave been reported to mimic cervical cystic tumours[24, 35].9.5 ParagangliomaICD-O:8680/1Paraganglioma, often referred to as chemodectoma, is atumour derived from paraganglia, structures of neuroectodermalcrest derivation that are found throughoutthe body. Paragangliomas are intimately associated withvascular and neural structures in the head and neckregion and are most commonly classified according totheir location: jugulotympanic, vagal, carotid body, andothers, including laryngeal, nasal and ocular [30, 61]. In