Fig. 6.1 Histology of a typical cervical lymph node. The trabeculae extending centrally from the periphery represent the lymph node hilum and contain, among other things, the blood vessels (asterisk). (Reproduced with kind permission of A. Agaimy MD, Institute of Pathology, Erlangen University Hospital, Germany.)

Fig. 6.2a Right side of the neck, transverse, level II. An oval lymph node in acute lymphadenitis colli (RF); the node has a delicate internal echo pattern with well-defined margins and measures 30 mm × 15 mm in both short-axis diameters. A clearly visible incidental finding is the nerve bundle of the vagus nerve seen in cross-section between the internal (ACI) and external (ACE) carotid arteries (asterisk). GSM, submandibular gland.

Fig. 6.2b Right side of the neck, longitudinal, level II. The oval lymph node seen in acute lymphadenitis colli measures 32 mm on its long axis.

Fig. 6.3 Left side of the neck, transverse, level V. This lymph node shows a characteristic pattern of inflammation (kidney shape, hilar sign, homogeneous texture). MSCM, stemocleidomastoid muscle, VJI, internal jugular vein, WS, vertebral spine.

Fig. 6.4 Left side of the neck, transverse, CCDS. A round, clearly defined lymph node lateral to the common carotid artery (ACC), with a classical “hilar sign” and hilar perfusion seen on CCDS. The afferent and efferent hilar vessels can also be identified at the right border of the node. In this case, the massive enlargement of the node with maintenance of the normal vascular and hilar structures was due to non-Hodgkin lymphoma. A cystic mass in the lower neck area may also be found with metastases of papillary thyroid carcinomas.

Fig. 6.5 Submandibular, right, transverse, CCDS. An oval lymph node with the classical configuration of an inflammatory lymph node: clear “hilar sign,” strong hilar perfusion visible with sub-vessels branching in the periphery.

Fig. 6.9 Left side of the neck, transverse, level V, CCDS. A round lymph node with ill-defined contours (asterisks) shows irregular vessel parts and pathways, totally unlike the normal central hilar perfusion pattern. Diagnosis: Lymph node metastasis.

Fig. 6.10 Left side of the neck, longitudinal, level IV, CCDS. Two round metastases without a “hilar sign” (RF) and with subcapsular perfusion. Besides the inhomogeneous internal echoes, there is also a more hypoechoic central area. Cranially, the belly of the omohyoid muscle (asterisk) can be seen in cross-section, and the carotid bulb is visible at the left edge of the image, clearly placing the nodes in level IV.

Fig. 6.11 Right side of the neck, level IV, split screen. Lying laterally to the internal jugular vein (VJI) is an enlarged oval, reactive lymph node; it has an L/S ratio of 2.0, is well demarcated, and shows the “hilar sign.” On the left of the image, another smaller lymph node with the same configuration can be seen medial to the vein. ACC, common carotid artery; MSCM, sternocleidomastoid muscle. Diagnosis: Acute lymphadenitis.

Fig. 6.12 Split screen, right side of the neck, level III. Lying between the internal jugular vein (VJI) and the common carotid artery (ACC) is an enlarged oval reactive lymph node; it has an L/S ratio of 2.0, is well demarcated, and shows the “hilar sign.”

Fig. 6.13 Split screen, left side of the neck, level V, CCDS. An enlarged oval reactive lymph node; it has an L/S ratio of 2.0, is well demarcated, and shows both the “hilar sign” and hilar perfusion. MTRAP, trapezius muscle. Diagnosis: Toxoplasmosis.

Fig. 6.14 Left side of the neck, transverse, level IV. A lymph node in level IV which, at first glance, appears oval and well demarcated. A polycyclic extension can be seen at the lateral end. This could be considered significant in a patient in whom malignancy is suspected, but the patient concerned had an acute respiratory tract infection. ACC, common carotid artery; MSCM, stemocleidomastod muscle; NV, vagus nerve; RF, lymph node; VJI, internal jugular vein; WS, vertebral spine.

Fig. 6.15 Left side of the neck, transverse, level IV. A lymph node metastasis (RF) with an irregular rounded shape and clearly defined margins. The echogenicity is homogeneous. ACC, common carotid artery; VJI, internal jugular vein.

Fig. 6.17 Floor of the mouth, transverse, level IA. Two round, space-occupying lesions (RF) with malignancy of the floor of the mouth. Besides the criterion of malignancy met in the ill-defined borders with the right digastric muscle (MD), both lymph nodes are round or polycyclic in shape. A further suspicious feature is the obvious inhomogeneity of the lymph node at the left edge of the image. MGH, geniohyoid muscle; MM, mylohyoid muscle. Diagnosis: Lymph node metastasis.

Fig. 6.18 Left side of the neck, longitudinal. An oval, well-demarcated lymph node in level II, bordering the bed of the parotid gland (GP). The echogenic structure corresponds to a “hilar sign.” Cranial to the oval, lymph node is what appears to be a further rounded space-occupying lesion with central echogenic septa. This, however, is the digastric muscle (MD) seen in cross-section, which may be confused morphologically with a lymph node. More cranially, three lymph nodes can be identified in the apex of the echogenic lower pole of the parotid. Lymph nodes at the inferior border of the parotid gland that are simultaneously neighbouring the latero-posterior aspect of the submandibular gland are also called ”Küttner’s lymph nodes.” Diagnosis: Acute lymphadenitis of the neck and the parotid gland in viral infection.

Fig. 6.19 Right side of the neck, level II/III. The space-occupying lesion with an inhomogeneous echo pattern lies on the external carotid artery (ACE) and internal carotid artery (ACI), medial to the internal jugular vein (VJI). Morphologically, a branchial cyst may appear similar, but would not show any intrinsic perfusion. MSCM, sternocleidomastoid muscle. Diagnosis: Lymph node metastasis.

Fig. 6.20 Split screen, right side of the neck, level IV, CCDS. The space-occupying lesion (RF) with an inhomogeneous echo pattern is sited laterally to the common carotid artery (ACC) and the internal jugular vein (VJI). The perfusion is peripheral and decentralized: in addition, irregular echogenic internal echoes are consistent with metastasis. MSCM, sternocleidomastoid muscle. Diagnosis: Lymph node metastasis.

Fig. 6.21 Split screen, right side of the neck, level III. A lymph node (RF) in a patient being followed up for malignant disease; the caudal margins show marked extension. Compared with the normal architecture, there is marked inhomogeneity. ACC, common carotid artery; VJI, internal jugular vein; MSCM, sternocleidomastoid muscle. Diagnosis: Lymph node metastasis recurrence, 6 months after initial multimodal treatment.

Fig. 6.22 A schematic representation of morphological changes in metastases. These morphological transfornations within a lymph node illustrate sonographic findings of malignancy.

Fig. 6.23 Left side of the neck, longitudinal, level III. A round lymph node metastasis with irregular borders has an anechoic center, which is indicative of necrosis caused by the metastatic transformation. VJI, internal jugular vein; MSCM, sternocleidomastoid muscle.

Fig. 6.24 Left side of the neck, level II. Medial to the internal and external carotid arteries, the round metastasis has an anechoic center consistent with central necrosis; this is considered to be a sign of malignancy. To the left, medial in the image, is an ill-defined hypoechoic primary tumor (TU) of the left side of the oropharynx. The internal jugular vein (VJI) is compromised and can be seen between the anterior border of the sternocleidomastoid muscle (MSCM) and the internal carotid artery (ACI). The vein can be demonstrated better with a Valsalva maneuver. ACE, external carotid artery.