Spleen/Thymus/ Lymph Node Flashcards
How is functional hyposplenism revealed?
Blood film findings of Howell-Jolly bodies (remnants of nucleus) and Pappenheimer bodies (siderotic granules-contains iron).
What is the most frequent cause of hyposplenism?
Surgical removal of the spleen eg after traumatic rupture.
Note: surgical removal can also occur after sickle cell anaemia, gluten-induced enteropathy and amyloidosis.
What are some indications for a splenectomy?
Splenic rupture, some cases of:
- chronic immune thrombocytopenia,
- hemolytic anaemia,
- chronic lymphocytic anaemia and lymphomas,
- primary myelofibrosis and
- tropical splenomegaly-like malaria.
Whats the function of the spleen?
- To remove aged or abnormal red cells, and excess DNA, nucleus remnants and siderotic granules, from intact red cells.
- Also has specialized immune function against encapsulated bacteria (macrophages present antigens to B and T cells to start adaptive immune response).
Patients with hyposplenism are at lifelong risk of infection from a variety of organisms. True or False.
True esp. encapsulated bacteria-Streptococcus pneumoniae, Haemophilus influenzae type B and Neisseria meningitidis
What is red pulp?
The cords and sinuses form the red pulp, which is 75% of the spleen and has an essential role in monitoring the integrity of red blood cells.
If the spleen is enlarged cuz of bone marrow aplasia, you should remove the spleen. T or F.
F- bcuz in that case the spleen has taken the role of making the red cells thats why its enlarged
- you can remove the spleen with bone marrow hyperplasia.
Thymic hypoplasia or aplasia is seen in what condition?
DiGeorge’s syndrome- accompanied by parathyroid developmental failures. This condition is marked by a total absence or severe lack of cell-mediated immunity and often hypoparathyroidism.
what is the function of the thymus?
to develop self-tolerance to antigens
thymic hyperplasia is characterized by what?
the presence of lymphoid follicles within the thymus
which disease is most frequently associated with thymic hyperplasia?
myasthenia gravis- 65% of the patients have thymic hyperplasia associated with increased lymphoid follicle size
note: thymomas are present in 15% of patients
majority of the tumours in the thymus are of what origin?
epithelial origin (thymomas)
90% of thymomas behave in what kind of fashion?
benign
A patient with low RBC or platelet count could possibly be a result of thymoma. T or F.
T- cuz thymomas can cause pancytopenia (21%)
what is lymphadenopathy?
lymph node enlargement; could be a result of neoplasia or inflammation
