<P> The taking of a medical history and exam by a medical practitioner can help point to the cause of the swelling, whether it be a localised infection, or a systemic disorder . Many symptoms or signs may point to the cause of swelling - for example, a sore throat and a cough may point to an upper respiratory tract infection as the cause of tonsil swelling . Changes in the appearance of a breast or a mass that has been felt may explain underarm pain and axillary lymph node swelling . Ongoing fevers or night sweats may suggest a systemic infection or a lymphoma as the cause of swelling . Depending on these findings, a wide variety of medical tests that include blood tests and scans may be needed to further examine the cause . A biopsy of a lymph node may also be needed . </P> <P> Lymphedema is another and fairly widespread condition that results in fluid retention and tissue swelling . It can be congenital as a result usually of undeveloped or absent lymph nodes, and is known as primary lymphedema . Secondary lymphedema usually results from the removal of lymph nodes during breast cancer surgery or from other damaging treatments such as radiation . It can also be caused by some parasitic infections . Affected tissues are at a great risk of infection . </P> <P> Lymph nodes can be affected by both primary cancers of lymph tissue, and secondary cancers affecting other part of the body . Primary cancers of lymph tissue are called lymphomas and include Hodgkin lymphoma and non-Hodgkin lymphoma . Cancer of lymph nodes can cause a wide range of symptoms from painless long - term slowly growing swelling to sudden, rapid enlargement over days or weeks . Lymphoma is managed by haematologists and oncologists </P> <P> Local cancer in many parts of the body can cause lymph nodes to enlarge, usually because of tumours cells that have metastasised into the node . Lymph node involvement is often a key part in the diagnosis and treatment of cancer, acting as "sentinels" of local disease, incorporated into TNM staging and other cancer staging systems . As part of the investigations or workup for cancer, lymph nodes may be imaged or even surgically removed . Whether lymph nodes are affected will affect the stage of the cancer and overall treatment and prognosis . </P>

A cancer that is concentrated in the lymph nodes is