A lymph node can often swell in the event of a common viral infection such as a cold, flu or Covid. But if it persists, you have to make sure that it is not a more serious reason like cancer.
Ganglia are small bean-shaped organs that are distributed throughout the bodywithin a network called lymphatic system, also composed of lymphatic vessels, tonsils, spleen. There are more than 800 located throughout the body: neck, armpit, groin (superficial lymph nodes) or even abdomen and thorax (deep lymph nodes). The lymph nodes are intended to defend the body against infections. and foreign agents. Concretely, the lymphocytes (white blood cells) will encounter the foreign agent (bacteria, virus for example in the case of infection) and fight it. This is the reason why these lymph nodes will swell if infectedamong other things, we then speak oflymphadenopathy (ADP). We distinguish between localized ADPs and multiple ADPs.
What can cause a lymph node to swell?
The lymph nodes can enlarge for various reasons. The most common cause of lymphadenopathy is infectious : viral syndrome like flu, cold, Covid, mononucleosis, toxoplasmosis or more rarely HIV…The lymph nodes swell where the infection is localized. “For example, in case of cough, rhinitis, with an ENT virus, it is the lymph nodes in the neck that swell., details Dr Clémentine Sarkozy. If the infection occurs at the genital or inguinal level, it is the inguinal lymph nodes that will increase in volume. A cut on the arm, if it becomes superinfected, can cause lymphadenopathy in the subaxillary lymph nodes or in the elbow. The orientation between a benign cause (infection, HIV, autoimmune disease for example) or malignant (i.e. tumor), such as a lymphoma, is based on multiple arguments, such as the number of ADP, but especially the duration of evolution. “Although this cause is much rarer, we must know how to eliminate it because lymphoma constitutes the 6th cancer in France with 20,000 cases per year.“, she continues.
Even if any lymphadenopathy should lead to consulting a doctor, certain elements may be suggestive of a lymph node of malignant origin:
► Evolution duration: A benign lymph node usually deflates within a few days. If the node does not disappear, a medical consultation is necessary:
► The size : lymph nodes measuring less than 1cm are not pathological;
► The appearance: a ganglion very hard, stony and very adherent to the deep plane;
► Pain : an inflammatory lymph node, linked to an infection, is readily painful ;
► Redness: local inflammation due to a sting or scratch will guide the doctor in his diagnostic hypotheses;
► Associated symptoms: a cold, a scratch, a tick bite or a cut cause benign lymphadenopathy. Conversely, certain clinical arguments are in favor of a malignant cause, particularly if the lymphadenopathy is accompanied by weight loss, sweating, nocturnal fever, fatigue, dyspnea, cough and unexplained itching.
Dr Sarkozy insists above all on the need to consult in the event of lymph node self-palpation, because no diagnosis can be made simply, and medical advice is always useful. The attending physician will be able to judge the need to do a biopsy, which will be the only element allowing a definitive diagnosis.
A lymph node that persists for more than a month: we do a biopsy!
The diagnosis is based on clinical examination. “The general practitioner will first look for one or more ADPs, then an infection in the drainage area, all around the swollen lymph node (bite, etc.), he will, for example, examine the breasts as ‘Axillary ADP, or the GE organs in the case of inguinal ADP… Then, he will examine the skin to see if there is any a pathological mole near the ADP. In all cases, a complete clinical examination is necessary. If he suspects a cancerous lymph node, he will refer the patient to a hematologist or oncologist. In case lymphadenopathy that has lasted for more than a month, a biopsy is systematically carried out“, indicates the hematologist.
Thanks to Dr Clémentine Sarkozy, hemato-oncologist at the Institut Curie in Saint Cloud and Paris.