Editing Lymphatic system (section)

==Clinical significance==
{{main|Lymphatic disease}}
The study of lymphatic drainage of various organs is important in the diagnosis, prognosis, and treatment of cancer. The lymphatic system, because of its closeness to many tissues of the body, is responsible for carrying cancerous cells between the various parts of the body in a process called [[metastasis]]. The intervening lymph nodes can trap the cancer cells. If they are not successful in destroying the cancer cells the nodes may become sites of secondary tumours.

<ref>Khan, A. R., Headland, S. E., Norling, L. V., & Lombardi, G. (2024). The emerging importance of lymphatics in health and disease: an update. *Journal of Clinical Investigation, 134*(1), e171582. https://doi.org/10.1172/JCI171582 </ref> The lymphatic system (LS) comprises lymphoid organs and a network of vessels responsible for transporting interstitial fluid, antigens, lipids, cholesterol, immune cells, and other materials throughout the body. Dysfunction or abnormal development of the LS has been linked to numerous diseases, making it critical for fluid balance, immune cell trafficking, and inflammation control. Recent advancements, including single-cell technologies, clinical imaging, and biomarker discovery, have improved the ability to study and understand the LS, providing potential pathways for disease prevention and treatment. Studies have shown that the lymphatic system also plays a role in modulating immune responses, with dysfunction linked to chronic inflammatory and autoimmune conditions, as well as cancer progression.

=== Imaging Techniques ===
Recent advancements in imaging modalities have significantly enhanced the visualization and understanding of the lymphatic system. Dynamic contrast-enhanced magnetic resonance [[lymphangiogram]] (DCMRL) technology has emerged as a non-invasive technique providing [[high resolution]] images of lymphatic vessels and nodes, aiding in the diagnosis of lymphatic disorders and guiding interventional procedures.<ref>{{Cite journal |last1=Itkin |first1=Maxim |last2=Nadolski |first2=Gregory J. |date=March 2018 |title=Modern Techniques of Lymphangiography and Interventions: Current Status and Future Development |url=http://link.springer.com/10.1007/s00270-017-1863-2 |journal=CardioVascular and Interventional Radiology |language=en |volume=41 |issue=3 |pages=366–376 |doi=10.1007/s00270-017-1863-2 |pmid=29256071 |issn=0174-1551}}</ref> 

Near-infrared fluorescence (NIRF) imaging utilizes [[indocyanine green]] as a contrast agent to offer real-time visualization of superficial lymphatic flow, proving valuable in both clinical and research settings. These technologies have revolutionized the assessment of lymphatic function and [[pathology]], facilitating early detection and treatment of related diseases.<ref>{{Cite journal |last1=Namikawa |first1=Tsutomu |last2=Sato |first2=Takayuki |last3=Hanazaki |first3=Kazuhiro |date=December 2015 |title=Recent advances in near-infrared fluorescence-guided imaging surgery using indocyanine green |url=http://link.springer.com/10.1007/s00595-015-1158-7 |journal=Surgery Today |language=en |volume=45 |issue=12 |pages=1467–1474 |doi=10.1007/s00595-015-1158-7 |pmid=25820596 |issn=0941-1291}}</ref>

===Enlarged lymph nodes===
{{Main|Lymphadenopathy}}
[[Lymphadenopathy]] refers to one or more enlarged lymph nodes. Small groups or individually enlarged lymph nodes are generally ''reactive'' in response to [[infection]] or [[inflammation]]. This is called ''local'' lymphadenopathy. When many lymph nodes in different areas of the body are involved, this is called ''generalised'' lymphadenopathy. Generalised lymphadenopathy may be caused by [[infection]]s such as [[infectious mononucleosis]], [[tuberculosis]] and [[HIV]], [[connective tissue disease]]s such as [[systemic lupus erythematosis|SLE]] and [[rheumatoid arthritis]], and [[cancer]]s, including both cancers of tissue within lymph nodes, discussed below, and [[metastasis]] of cancerous cells from other parts of the body, that have arrived via the lymphatic system.<ref name=DAVIDSONS2010B>{{cite book |editor-first1=Nicki R. |editor-last1=Colledge |editor-first2=Stuart H. |editor-last2=Ralston |editor-first3=Brian R. |editor-last3=Walker |name-list-style= vanc |title=Davidson's principles and practice of medicine |date=2011 |publisher=Churchill Livingstone / Elsevier |location=Edinburgh / New York |isbn=978-0-7020-3085-7 |pages=1001, 1037–1040 |edition=21st |oclc=844959047}}</ref><ref name= Moore1961>{{cite journal | vauthors = Moore GE |title= Tumour cells and their spread |journal= Can Med Assoc J |date=May 1961 | volume = 84| issue = 19|pages=1051–1053|doi= |pmid=13772299 |pmc= 1939597}}</ref>

===Lymphedema===
{{Main|Lymphedema}}
[[Lymphedema]] is the [[edema|swelling]] caused by the accumulation of lymph, which may occur if the lymphatic system is damaged or has malformations. It usually affects limbs, though the face, neck and abdomen may also be affected. In an extreme state, called [[elephantiasis]], the edema progresses to the extent that the skin becomes thick with an appearance similar to the skin on [[elephant]] limbs.<ref>{{Cite web | first =  James D. | last = Douketis | name-list-style = vanc | title = Lymphedema| url = http://www.merck.com/mmhe/sec03/ch037/ch037b.html | work = Merck Manual }}</ref>

Causes are unknown in most cases, but sometimes there is a previous history of severe infection, usually caused by a [[parasitic disease]], such as [[lymphatic filariasis]].

[[Lymphangiomatosis]] is a disease involving multiple cysts or lesions formed from lymphatic vessels.{{Off topic sentence|date=June 2019}}

Lymphedema can also occur after [[Lymphadenectomy|surgical removal of lymph nodes]] in the armpit (causing the arm to swell due to poor lymphatic drainage) or groin (causing swelling of the leg). Conventional treatment is by [[manual lymphatic drainage]] and [[compression garment]]s. Two drugs for the treatment of lymphedema are in clinical trials: Lymfactin<ref name=lymfactin>{{Cite web| last = Herantis Pharma| title = Lymfactin® for lymphedema| date = 2015-07-21| url = http://herantis.com/pipeline/lymfactin-for-lymphedema/| access-date = 2018-12-28| archive-url = https://web.archive.org/web/20181208163642/http://herantis.com/pipeline/lymfactin-for-lymphedema/| archive-date = 2018-12-08| url-status = dead}}</ref> and [[Ubenimex]]/[[Bestatin]]. There is no evidence to suggest that the effects of manual lymphatic drainage are permanent.<ref>{{cite journal | vauthors = Martín ML, Hernández MA, Avendaño C, Rodríguez F, Martínez H | title = Manual lymphatic drainage therapy in patients with breast cancer related lymphoedema | journal = BMC Cancer | volume = 11 | issue = 1 | pages = 94 | date = March 2011 | pmid = 21392372 | pmc = 3065438 | doi = 10.1186/1471-2407-11-94 | doi-access = free }}</ref>

===Cancer===
[[File: Reed-Sternberg lymphocyte nci-vol-7172-300.jpg|thumbnail|[[Reed–Sternberg cell]]s ]]
{{Main|Lymphoma}}
[[Cancer]] of the lymphatic system can be primary or secondary. [[Lymphoma]] refers to cancer that arises from [[lymphatic tissue]]. Lymphoid leukaemias and lymphomas are now considered to be tumours of the same type of cell lineage. They are called "leukaemia" when in the blood or marrow and "lymphoma" when in lymphatic tissue. They are grouped together under the name "lymphoid malignancy".<ref name="FauciBraunwald2009">{{cite book| first1 = Anthony S. | last1 = Fauci | first2 = Eugene | last2 = Braunwald | first3 = Dennis | last3 = Kasper | first4 = Stephen | last4 = Hauser | first5 = Dan L. | last5 = Longo | name-list-style = vanc |title=Harrison's Manual of Medicine |url= https://books.google.com/books?id=66XKIuh8P-AC&pg=PA352 |access-date=12 November 2010 |date=19 March 2009 |publisher=McGraw Hill Professional |isbn=978-0-07-147743-7 |pages=352–}}</ref>

Lymphoma is generally considered as either [[Hodgkin lymphoma]] or [[non-Hodgkin lymphoma]]. Hodgkin lymphoma is characterised by a particular type of cell, called a [[Reed–Sternberg cell]], visible under microscope. It is associated with past infection with the [[Epstein–Barr virus]], and generally causes a painless "rubbery" lymphadenopathy. It is [[cancer staging|staged]], using [[Ann Arbor staging]]. [[Chemotherapy]] generally involves the [[ABVD]] and may also involve [[radiotherapy]].<ref name=DAVIDSONS2010B /> Non-Hodgkin lymphoma is a cancer characterised by increased proliferation of [[B-cell]]s or [[T-cells]], generally occurs in an older age group than Hodgkin lymphoma. It is treated according to whether it is ''[[Grading (tumors)|high-grade]]'' or ''low-grade'', and carries a poorer prognosis than Hodgkin lymphoma.<ref name=DAVIDSONS2010B />

[[Lymphangiosarcoma]] is a malignant [[soft tissue sarcoma|soft tissue tumour]], whereas [[lymphangioma]] is a benign tumour occurring frequently in association with [[Turner syndrome]]. [[Lymphangioleiomyomatosis]] is a benign tumour of the smooth muscles of the lymphatics that occurs in the lungs.

[[Lymphoid leukaemia]] is another form of cancer where the host is devoid of different lymphatic cells.

===Other===
{{div col|colwidth=18em}}
* [[Castleman's disease]]
* [[Chylothorax]]
* [[Kawasaki disease]]
* [[Kikuchi disease]]
* [[Lipedema]]
* [[Lymphangitis]]
* [[Lymphatic filariasis]]
* [[Lymphocytic choriomeningitis]]
* [[Solitary lymphatic nodule]]
{{div col end}}