Lymph nodes Flashcards
2 main components of lymphatic system
a conducting system (lymph vessels) which transport lymph from the interstitium to the circulation
lymphoid tissue (lymph nodes, MALT, spleen etc)
role of lymph in the immune system
lymph transports antigen-presenting cells (APCs) to the lymph nodes and MALT
what is each lymph node comprised of
Each node is composed of a mass of lymphoid tissue surrounded by a fibrous capsule
Proliferation of T and B lymphocytes in the germinal centres
Germinal centres sample the incoming fluid and decide whether an immune response is needed
causes of lymphadenopathy
Malignant tumour
Primary ie. lymphoma
Secondary (metastatic tumour such as carcinoma or melanoma)
Reactive to infection
acute infection eg. influenza, infectious mononucleosis
chronic infection eg. TB, HIV
Multisystem disorders
eg. sarcoidosis, SLE, Rheumatoid arthritis
causes of neck lumps
Thyroid (rise on swallowing)
Salivary gland
Cysts derived from embryological remnants
Skin and subcutaneous tissue lesions which may occur anywhere eg. sebaceous cyst, lipoma
what do reed sternberg cells indicate
hodgkin lymphoma
RFs for hodgkin lymphoma
history of Epstein Barr Virus (EBV) infection
immunosuppression eg. HIV infection
family history
staging used for lymphoma
ann arbour
broad categories of NHL
B cell–> indolent or aggressive
T cell
what is sarcoidosis?
It is a multisystem disease of unknown aetiology characterised by the presence of non-caseating granulomas in tissues and organs
what systems does sarcoidosis affect
Sarcoidosis can involve virtually any organ of the body, but some are involved more than others:
Lymph nodes. Virtually all cases of sarcoidosis involve lymph nodes. Any lymph node may be involved but the most common are the hilar and mediastinal nodes. Enlargement of these nodes is usually picked up on a chest radiograph.
Lungs. The lungs are frequently involved by sarcoidosis. Healing of the granulomas may lead to varying degrees of lung fibrosis. Severe sarcoidal lung disease may lead to right heart failure and respiratory failure.
Skin. Skin lesions due to non-caseating granulomas often manifest with an asymptomatic maculopapular rash seen on the face and the trunk. One characteristic pattern is the appearance of purple shiny rubbery plaques on the nose, known as lupus pernio. Erythema nodosum may be associated with sarcoidosis.
Eyes. Sarcoidosis involving the eyes typically causes uveitis, meaning inflammation of the uveal tract. Anterior uveitis, which causes a red, painful eye with photophobia, is often self-limiting. Posterior uveitis, which causes floaters due to inflammatory cells appearing in the vitreous with some blurring of vision, is the more chronic form of the disease.
Lacrimal and salivary glands. Involvement of the lacrimal and salivary glands may lead to dry eyes and dry mouth.
Nervous system. Sarcoidosis can affect the central and peripheral nervous systems. A CNVII palsy is a common complaint in sarcoidosis. Hypothalamic involvement is also common, resulting in diabetes insipidus due to destruction of the ADH-producing neurones.
tests for sarcoidosis
ESR is often raised
Hypercalcaemia is seen in about 10% of cases due to conversion of vitamin D into active 1,25-dihydroxycholecalciferol in the granulomas
serum levels of angiotensin-converting enzyme (ACE) are raised in most patients with active sarcoidosis
