Spleen and Thymus, Putthoff Flashcards
functions of the spleen
phagocytosis
Ab production
Hematopoiesis
Sequestration of formed blood elements
What are splenectomy patients prone to
infections from S pneumonia, N meninginitis, H influenza
Where in spleen do you find Ab secreting plasma cells
red pulp
What infections can cause splenomegaly
mononucleosis
what type of congestive disorders can cause splenomegaly
cirrhosis, R HF, portal thrombosis
how does increased Portal v Pressure lead to splenomegaly
increased deposition of collagen from increased pressure leads to dilation and slowing of blood so more is in spleen and mroe is destoryed
what are causes of portal thrombosis
intrahepatic obstructive diseases or carcinomas of the stomach or pancreas
what are Sx of splenomegaly
LUQ pressure abdominal discomfort thrombocytopenia anemia leukopenia
What lymphohematogenous disorders are assoc with splenomegaly
non-hodgkin lymphoma and lymphocytic leukemia
myeloproliferative disorders
what immune inflammatory proccesses are assoc with splenomegaly
SLE and RA
What is nons[ecific acute splenitis
secondary to any blood borne infections
mild splenomegaly
soft and fluctuant
acute congestion red pulp
what are the infiltrates composed of in nonspecific acute splenitis
neutrophils, plasma cells and maybe eos
Why do the spleens commonly infarct
lacks collarteral blood supply
usually emboli from endocarditis or damage from sickle cell
What do splenic infarcts look like
bland pale, wedge shaped and subcapsular
Describe neoplasms of the spleen
primary are extremely rare- hemangiomas and lymphangiomas
secondary are assoc with myeloproliferative syndromes or myeloid neoplasms (DLBCL common)
What are the congenital problems with spleens
absent- rare assoc with situs inversus
hypoplasia- common
accessory- common
what is important to check before providing Tx splenectomy
look for accessory spleen
what can cause rupture of spleen
trauma
mono, malaria, typhoid fever, lymphoid neoplasm
are chronic spleens with splenomegaly at increased risk of rupturing
no decreased because of all the fibrotic proccesses
Describe size of thymus over time
gets bigger than in adulthood shrinks to basicall just fatty fibrotic tissue
what can make thymus involute earlier on
severe illness or HIV
What cells are found in thymus
epithelial cells
immature T lymphocytes
macrophages, dendritic cells, B lymphocytes, neutrophils, eos, myoid cells
what are thymic epithelial cells in the medulla like
densely packed, spindle shaped called hassel corpuscles
keratinized cores
what marker stains the medullary epithelial cells in thymus
HLA-DR+
describe the cortical thymic epithelial cells
polygonal with lots of cytoplasm
what is role of immature T lymphocytes in thymus
go through Ag dep T cell maturation
- and + selection
What are the developmental disorders of thymus
Digeorge 22q11 which has severe defects in cell mediated immunity and assoc with hypothyroidism
What are thymic cysts
benign usually less than 4 cm and stratified squamous- columnar epithelium
fluid inside is serous or mucinous
If you found a cystic thymic mass what do you need to look for
neoplasm
What is thymic hyperplasia
thymic follicular hyperplasia of B lymphocytes
thymic hyperplasia is common in what other conditions
myasthenia gravis
graves, SLE, RA, scleroderma
What are thymomas
tumors of the thymic epithelial cells
what do the thymomas look like
lobulated gray-white masses often encapsulated
what are the types of thymomas
cytologically benign noninvasive
malignant I/cytologically benign and invasive
malignant II cytologically metastatic
where are thymomas usually found
anterosuperior mediastinum, neck, thyroid, pulmonary hilus, posterior mediastinum
dist thymomas
> 40 M=F rarely in children
what is prognosis of type I bengin but invasive thymoma
minimal invasion with complete excision 5 yr survival >90%
extensive invasion 5 yr survival <50%
what are the subtypes of II malignant thymoma
squamous cell carcinoma
lymphoepithelioma
lymphoepithelioma thymomas are assoc with what commonly
EBV
what do metastatic thymomas look like
fleshy and obviously invasive
Sx of thymomas
impingement of mediastinal structures
What are thymomas assoc with
myasthenia gravis!
hypogammaglobulinemia, pure red cell aplasia, graves, pernicious anemia, dermatomyositis-polymyositis and cushings
which type thymomas are more common assoc with autoimmune
cortical thymomas
