Benign Lymph Node Enlargement, Spleen & Thymus Flashcards
What causes paracortical hyperplasia in a lymph node?
T cell-mediated immune response that causes activation of T cells and shrinking of B cell follicles
What is the cause of sinus histiocytosis in lymph nodes?
Expansion of macrophages in nodal subcapsular and trabecular sinuses
Thymic hyperplasia is most frequently seen with what autoimmune disorder?
Myasthenia gravis
What are possible causes of congestive splenomegaly?
Systemic venous congestive, liver cirrhosis, portal vein thrombosis
What are potential causes of non-caseating granulomatous lymphadenitis?
Sarcoidosis, toxoplasmosis
What are common viral causes of paracortical hyperplasia?
Mononucleosis, varicella-herpes zoster, measles, HSV
What are potential causes of caseating granulomatous lymphadenitis?
TB, leprosy, cat scratch disease, fungal infections
Infection with this parasite may cause chronic splenitis and give the spleen a gray to black color.
Malaria
Where are B cells located in a lymph node?
Follicle/Germinal centers
What is functional asplenia?
Loss of spleen function often due to multiple infarcts. Sickle cell disease is the most common cause
What histologic findings are characteristic of sarcoid granulomas in lymph nodes?
Non-caseating granulomas with Asteroid bodies & Schaumann bodies
Caseating granulomas with Langhan’s multinucleated giant cells are associated with what pathology?
Tuberculosis
What histologic findings are characteristic in a patient with asplenia?
Howell-Jolly Bodies & Target Cells
Thymic hypoplasia is often associated with what congenital disorder?
DiGeorge Syndrome (22q11 deletion
Thymomas are neoplasms of what cell type?
Epithelial cells
True/False. In cases of HIV lymph node hyperplasia, follicle boundaries are blurred.
True - this is due to extraversion of RBCs into the germinal centers and depletion of lymphocytes
True/False. The spleen is rarely impacted by infarcts due to extensive collateral blood supply.
False - the spleen is one of the most common sites where emboli lodge. Splenic infracts are common due to poor collateral blood supply
What is the histologic presentation of acute nonspecific lymphadenitis?
Germinal centers with numerous mitotic figures, macrophages with debris, increased neutrophils
This type of granulomatous lymphadenitis involves central areas of necrosis within a granuloma.
Caseating granulomatous lymphadenitis
What histologic findings are seen in necrotizing lymphadenitis and with what disease are they associated?
Stellate necrotizing granulomas due to Cat-Scratch Disease
Where do most thymomas arise?
Anterior superior mediastinum - symptoms are due to impingement on mediastinal structures
What is the pathophysiology of acute splenomegaly?
Acute congestion of the red pulp. Infiltration with neutrophils and plasma cells may cause acute splenitis
True/False. The spleen may take over RBC production when the bone marrow is not producing enough RBCs.
True - this is called extramedullary hematopoiesis
“Onion skin” thickening of splenic arteries is associated with what condition?
SLE
