[Use of clinical ultrasound in Primary Care: Lynphadenopathy]

Lymphadenopathy is the alteration in the consistency or size of a lymph node. It is often associated with benign diseases, although factors such as gender, location, comorbidities, and the patient's age can increase the percentage of malignancy. Infections, tumors, and systemic diseases are its most common causes. Ultrasound allows the study of superficial and some deep lymph nodes through transverse and longitudinal planes, also using color Doppler to examine their vascularization. The ultrasound characteristics of a normal lymph node include an oval shape, well-defined borders, a long/short axis ratio>2cm, hypoechoic and homogeneous cortex, echogenic and vascularized central hilum, and short axis<1cm, except in certain cases. Ultrasound is a useful tool that, in conjunction with the medical history, physical examination, and laboratory tests, allows for a diagnostic approach in the study of lymphadenopathy. It helps differentiate them from other processes and to make an early referral if necessary.