Our aim is to assess the role of the gray scale and color Doppler ultrasound in diagnosis of the different pediatric neck masses .

Neck masses are a common occurrence in the pediatric population and often represent a diagnostic challenge for the clinician involved . fortunately , the vast majority of these lesions are ultimately proven to be benign in nature (1).

Even though clinical examination and patient's history are the first and indispensable steps in the initial diagnosis, the role of imaging is crucial, not only to determine whether a mass represents a true tumour or not , but also to achieve a more correct diagnosis and determine the extension of the lesion and its relation with the nearby anatomic structures (2).

Ultrasound (US) should serve as the primary initial imaging modality in children for palpable masses and assessment of superficial glandular structures. Because of the smaller neck size and less subcutaneous fat, sonographic penetration and resolution is generally improved as compared with adults (3 ).

Doppler imaging can also elucidate how flow is distributed within a mass may have diagnostic significance and help us in determining the nature of the lesion as well as it is of great importance in assessment of vascular lesions (4)

Though ultrasound is most common method used for evaluation of pediatric neck masses , and CT as well as MRI are used as an additional tool when necessary ( 3 ) , few studies have looked at the sensitivity and specificity of the different imaging modalities of the pediatric neck masses and most studies have investigated the epidemiology of the pediatric neck masses (5) which make histopathological diagnosis still the gold standard in distinguishing the etiology of pediatric neck masses and ruling out malignant disease (6)

Inclusion Criteria:

- Clinical cases who are suspected for and provisionally diagnosed for "neck swelling" in children (below age of 18 years).

Exclusion Criteria:

1. Patients with conditions that may hinder ultrasound examination like subcutaneous emphysema and thick skin scarring.
2. Patients who are unwilling/uncooperative or have not given consent for participation.

pediatric patients with neck masses attending at outpatient clinics at assiut university pediatric hospital.