[Ultrasonography of cervical cysts and their differential diagnosis].

Among 22 proven branchiogenic or thyreoglossal cysts, 15 presented with a characteristic pattern of homogeneous smooth reflections within a well-demarcated thin and elastic, deformable wall when using a high-resolution transducer. The other cases, showing an inhomogeneous texture and/or irregular walls, cannot be distinguished from inflammatory or neoplastic processes with central necrosis. Complete surgical removal is recommended especially in these latter cases. One case of malignant transformation was found.