Diseases of Lymph Nodes PDF

Diseases of Lymph nodes Prof Dr Nafissa El Badawy Lymph node normal histology  LYMPHATIC SYSTEM Lymphadenopathy refers to a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy or LN enlargement may be inflammatory or neoplastic LYMPH NODE DISTRIBUTI...

Diseases of Lymph nodes Prof Dr Nafissa El Badawy Lymph node normal histology  LYMPHATIC SYSTEM Lymphadenopathy refers to a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy or LN enlargement may be inflammatory or neoplastic LYMPH NODE DISTRIBUTION ACUTE LYMPHADENITIS I-Acute non-specific Lymphadenitis; It occurs in nodes draining acutely inflamed focus as in acute suppurative tonsilitis Morphology; Gross; acutely inflamed nodes are enlarged & tender U/M: there are large germinal centers Neutrophilic infiltrate with abscess formation may be seen in severe cases  Chronic non specific lymphadenitis Definition Changes in lymph node due to prolonged inflammatory, infective, …. etiology. It is referred to as reactive hyperplasia It is the commonest cause for lymph node enlargement Here is the normal appearance of a benign reactive lymph node. At the top is the capsule and just under that a subcapsular sinus where lymphatics enter that drain tissues peripheral to the node. Beneath the capsule is the paracortical zone with lymphoid follicles having a pale germinal center in which the immune responses are often generated. Beneath this are sinusoids extending to the center of the node. Chronic specific lymphadenitis: TB lymphadenitis Sarcoidosis Syphilis Cat scratch disease Infectious mononucliosis Toxoplasmosis  Tuberculosis of Lymph Nodes ‘TB lymphadenitis’ TB lymphadenitis is a common cause of lymph node enlargement. It is usually a primary infection in children The commonest sites are: Cervical LNs; infected from tonsils Medistinal LNs; infected with primary pulmonary TB Mesenteric LNs; infected due to ingestion of infected milk (Tabes mesenterica) Microscopically: Early tuberculous lymphadenitis; there is infiltration by multiple small, pale tubercles formed of aggregates of epithelioid cells, few Langhan’s giant cells & minimal caseation  Caseating tuberculous lymphadenitis; most of nodal tissue is replaced by areas of caseous necrosis with multiple small tubercles at the periphery  Caseating Early  Cold abscess??? It is formed by accumulation & liquefaction of caseous material, surrounded by TB granulation tissue & fibrosis It complicate TB of LN, bone & joints and epididymis It may open to outside ---► multiple sinuses  SARCOIDOSIS Sarcoidosis is an inflammatory disease of unknown cause that affects multiple organs in the body, but mostly the lungs and lymph nodes. In people with sarcoidosis, abnormal masses (Non caseating granulomas) are formed in different organs. Morphology Microscopically: There is non-caseating well circumscribed epithelioid granulomata with giant cells surrounded by lymphocytes Two characteristic inclusions are seen inside giant cells; * Schaumann bodies (laminated calcified bodies) * Astroid bodies (star shaped inclusions) ……Fibrosis Lymph node, sarcoidosis INFECTIOUS MONONUCLEOSIS It refers to a group of symptoms caused by the Epstein-Barr virus (EBV). It occurs in teenagers, but can occur at any age. The virus is spread through saliva, which is why some people refer to it as “the kissing disease.” Symptoms: Pain; Sore throat; Fever; Jaundice  Cat scratch disease (CSD) Is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry the infection at some point. The infection does not make cats sick. However, the scratch or bite of an infected cat can cause symptoms in people, including swollen lymph nodes forming stellate abscess