Mistakes in ultrasound diagnosis of superficial lymph nodes

The article discusses basic mistakes that can occur during ultrasound imaging of superficial lymph nodes. Ultrasound is the first imaging method used in the diseases of superficial organs and tissues, including lymph nodes. The causes of mistakes can be either dependent or independent of the performing physician. The first group of mistakes includes inappropriate interpretation of images of anatomical structures, while the latter group includes, among other things, similar ultrasound images of different pathologies. For instance, a lymph node, whether normal or abnormal, may be mimicked by anatomical structures, such as a partially visible, compressed vein. Lymph nodes in lymphomas may be indistinguishable from reactive lymph nodes, even when using Doppler option, as well as morphologically difficult to distinguish from metastases. Metastatic lymph nodes can mimic e.g. nodular, separated postoperative thyroid fragments, a lateral neck cyst, chemodectoma (carotid body tumor) or neuroma. The appearance of lymph nodes in granulomatous diseases, such as tuberculosis or sarcoidosis, can be very similar to that of typical metastatic lymph nodes or lymphomas. Anechoic or hypoechoic areas in a lymph node can represent necrosis or metastatic hemorrhages, but also suppuration in inflamed lymph nodes. Lymph nodes in lymphomas, metastatic and reactive lymph nodes can adopt the classical characteristics of a simple cyst. The overall ultrasound picture along with all criteria for the assessment of a lymph node should be taken into account during ultrasound imaging. It seems that the safest management is to refer patients diagnosed with lymph node abnormalities for ultrasound-guided targeted fine needle aspiration biopsy followed by a total lymph node resection for histopathological examination in the case of suspected lymphoma.