الفهرس 
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Abstract
Cervical lymph nodes are composed of lymphoid tissue and are located along the lymphatic vessels of the neck. There are about 300 lymph nodes in the neck, and the lymph nodes are embedded in the soft tissues of the neck and are either partially or completely surrounded by fat. Each cervical lymph node is encapsulated by fibrous tissue and is divided into cortical and medullary regions (Ahuja, 2005).Cervical lymphadenopathy is defined as lymph node (LN) enlargement. Causes of lymphadenopathy are varied and may be inflammatory, autoimmune, or neoplastic (Kerawala, 2010). Age of the patient play important role in diagnosing causes of cervical lymphadenopathy. Generally, the cause of LN swelling in young patients from infants to adolescents is benign in over 80% of cases. This figure decreases considerably with age, to the extent that a malignant cause is found in over 60% of patients age 50 and above, however if there is a suspicion of malignancy in a young patient, the most frequent causes in children are acute leukemia and non Hodgkin lymphoma (NHL). In adult and old age NHL and Hodgkin lymphoma (HL) are roughly equal Esen, 2006). Evaluation of cervical nodes is an important procedure for patients with head and neck lesions because it assesses the prognosis of the patients and helps to select appropriate treatment. Ultrasound is a useful imaging tool for initial evaluation of cervical lymph nodes because it has a high sensitivity and specificity particularly when combined with fine-needle aspiration cytology (FNAC) (Ahuja, 2003). The role of high-resolution ultrasound (US) in assessment of cervical LNs is well established, and grey-scale US is widely used to assess cervical nodes for their number, site, size, nodal boundary, hilum, matting, adjacent soft tissue edema and other internal nodal echo patterns. Combined color Doppler US and Doppler waveform analysis of nodal vascularity will improve accuracy in differentiating benign from malignant cervical lymphadenopathy (Ying et al., 2002).Multidetector computed tomography (MDCT) allows detailed evaluation of the anatomy and pathology of the neck and thoracic inlet. The major structures are identified by their appearance and that of contrasting fatty tissue planes surrounding the soft tissues. These structures include the larynx, trachea, thyroid, and parathyroid glands as well as the vessels, LN chains, nerves, and supporting muscles (Sliverman, 2005). Contrast-enhanced CT may be used to further characterize the extent of sonographic abnormalities and to confirm deep nodal abnormalities. Benefits include superior anatomic localization; determination of size, number, shape, borders, internal architecture, and enhancement characteristics of nodes and evaluation of perinodal soft tissues and related head and neck findings (Benjamin et al., 2012)