Carotid Body tumor

Despite the frequent appearance in literature, these tumors are rather uncommon. Carotid body tumor is the second most frequent nonchromaffin paraganglioma (after the glomus jugulare tumor). It has been proposed that tumor might not be a neoplasm, but a normal proliferative reaction of the organism to several unknown factors. Bungeler (1952) suggested that the carotid body tumor could be a type of adaptive hyperplasia, provoked by trauma of the cortical projection fields of the vagus nerve. However, many of the lesions are malignant and sometimes give matastases. This proves that the carotid body tumor is, in fact, a neoplasm.Study of the familial occurrence of chemodectomas has established a certain genetic influence on the development of these tumor. The hereditary factor can be especially significant in multicentric cases.Saldana et al. (1973) stated that chemodectomas were 10 times more frequent in high-altitude inhabitants than in sea-level residents. They suggested that lifelong hypoxia stimulated chemoreceptor tissue hyperplasia, which in the end caused tumor formation.These tumors are diagnosed in all stages of life, but there is a slight predilection for women in the incidence of carotid body tumors. There is no preferential laterality. The tumor can be characterized by slow growth. On physical examination a lateral cervical mass that is pulsatile can be found. Superior and medial extension of the lesion may cause a pharyngeal bulge and displace the tonsil, soft palate and uvula. The extension into the nasopharynx is rare. Patients may complain of pain and dysphagia. Syncope with or without associated diaphoresis, nausea, trembling, blurred vision may be experienced. Hoarseness and cough with dyspnea are also possible symptoms. Carotid body tumor can lead to Horners syndrome. Differential diagnosis includes lymphadenitis, branchial cleft cyst, metastatic carcinoma, lymphoma, neurogenic tumors, salivary gland tumors, aneurysm, giant cell arteritis, hematoma, carotid calcification. Diagnostic procedures consist of CT with contrast, carotid angiography and MRA.