Lymphadenopathy oradenopathy is adisease of thelymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of aninflammatory type (the most common type) islymphadenitis,[1] producingswollen or enlarged lymph nodes. In clinical practice, the distinction between lymphadenopathy and lymphadenitis is rarely made and the words are usually treated assynonymous. Inflammation of thelymphatic vessels is known aslymphangitis.[2] Infectious lymphadenitis affectinglymph nodes in the neck is often calledscrofula.
Lymphadenopathy is a common and nonspecificsign. Common causes includeinfections (from minor causes such as thecommon cold and post-vaccination swelling to serious ones such asHIV/AIDS),autoimmune diseases, andcancer. Lymphadenopathy is frequentlyidiopathic and self-limiting.
The most distinctive sign ofbubonic plague is extreme swelling of one or more lymph nodes that bulge out of the skin as "buboes". The buboes often becomenecrotic and may even rupture.[5]
Immunocompromised:AIDS. Generalized lymphadenopathy is an early sign of infection withhuman immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS).[20] "Lymphadenopathy syndrome" has been used to describe the first symptomatic stage ofHIV progression, preceding a diagnosis of AIDS.
Thesemorphological patterns are never pure. Thus, reactive follicular hyperplasia can have a component of paracortical hyperplasia. However, this distinction is important for thedifferential diagnosis of the cause.
Medical ultrasonography of a typical normal lymph node: smooth, gently lobulated oval with a hypoechoic cortex measuring less than 3 mm in thickness with a central echogenic hilum.[26]Ultrasonography of a suspected malignant lymph node: - Absence of the fatty hilum - Increased focal cortical thickness greater than 3 cm -Doppler ultrasonography that shows hyperaemic blood flow in the hilum and central cortex and/or abnormal (non-hilar cortical) blood flow.[26]
Onultrasound,B-mode imaging depicts lymph node morphology, whilstpower Doppler can assess the vascular pattern.[28] B-mode imaging features that can distinguishmetastasis andlymphoma include size, shape, calcification, loss ofhilar architecture, as well as intranodal necrosis.[28] Soft tissue edema and nodal matting on B-mode imaging suggeststuberculous cervical lymphadenitis or previousradiation therapy.[28] Serial monitoring of nodal size and vascularity are useful in assessing treatment response.[28]
Fine-needle aspiration cytology (FNAC) hassensitivity and specificity percentages of 81% and 100%, respectively, in thehistopathology of malignant cervical lymphadenopathy.[27]PET-CT has proven to be helpful in identifying occult primary carcinomas of the head and neck, especially when applied as a guiding tool prior to panendoscopy, and may induce treatment related clinical decisions in up to 60% of cases.[27]
Size, where lymphadenopathy in adults is often defined as a short axis of one or more lymph nodes greater than 10 mm.[29]
Extent:
Localized lymphadenopathy: due to localized spot of infection; e.g., an infected spot on the scalp will cause lymph nodes in the neck on that same side to swell upInflammatory localized lymphadenopathy at right mandibular angle
Size, where lymphadenopathy in adults is often defined as a short axis of one or more lymph nodes greater than 10 mm.[29][30] However, there is regional variation as detailed in this table:
Lymphadenopathy of theaxillary lymph nodes can be defined as solid nodes measuring more than 15 mm without fatty hilum.[36] Axillary lymph nodes may be normal up to 30 mm if consisting largely of fat.[36]
In children, a short axis of 8 mm can be used.[37] However, inguinal lymph nodes of up to 15 mm and cervical lymph nodes of up to 20 mm are generally normal in children up to age 8–12.[38]
Lymphadenopathy of more than 1.5–2 cm increases the risk ofcancer orgranulomatous disease as the cause rather than onlyinflammation orinfection. Still, an increasing size and persistence over time are more indicative of cancer.[39]
^Page 942 in:Richard M. Gore, Marc S. Levine (2010).High Yield Imaging Gastrointestinal HIGH YIELD in Radiology. Elsevier Health Sciences.ISBN9781455711444.
