the splenomegaly power point dr. cosmescu

8/13/2019 The SPLENOMEGALY Power Point Dr. Cosmescu

1/29

THE SPLENOMEGALY


2/29

The splenomegaly is a quite commonfinding in acute or chronic illnesses.

It is rarely isolated, in most casesbeing accompanied by hepatomegaly,the hepatosplenomegalic syndrome, in

which, either spleen or liverenlargement may be most evident.


3/29

Structure of the spleen. The spleen is a parenchymal organ, situated in the

left hypocondrium. The spleen weights about 200g

and is enveloped by a fibrous capsule, which is theorigin for fibrous extension ( Sept) that dividethe organ into several lobules.

The functional tissuehas two divisions : -the white pulp, organised in lymph nodes(

Malpyghis corpuscles) and lymphoid sheathsthatthat surround the small arteries. The spleen corpusclescontain type B lymphocytes

the thymusdependent zone, while the lymphoidsheathscontain type Tlymphocytes the

independent zone. -the red pulp is situated among the lymphoidstructures and it consists of spleen sinusesandspelling cords( the Billroths cords) suspended ina reticulo-histiocitar tissue.


4/29

The functions of the spleenshould be

understood in terms of the cumulated functionsof the reticulo-histiocitar system and the

lymphatic system. In addition, the spleen has atight relationship with the other two importantconglomerations of the reticulo-histiocitar system: the liver and the bone marrow, a continuousneuro-hormonal communication taking place

between them. Originality of the spleen consists of its uniquevascular system, made of capillaries and sinuseswith discontinuous walls, that have the capacity ofa filter.

The situation of the spleen between thesystemic and portal blood circulation, and itscapacity to increase its volume explain theimportant role the spleen plays in thehemodynamic regulation of these territories.


5/29

The spleen has several functions : 1). The hemodynamic function :

a).Storage site for the blood :of smallimportance in the healthy individual, it becomes important in case of

hypertrophy when up to 20% of the totalerythrocytes can be stored inside the spleen.Although hemolysis does not occur to a big extentin this pool, a prolonged sequestration may lead toa brittleness of the erythrocyte walls even innormal cells.

During a loss of blood or a hypoxic state, thespleen is able to contract in order to release

erythrocytes, leukocytes and platelets in thecirculating blood.


6/29

b).Being an extensible vascular spongeconnected with the portal circulation, the spleenregulates the level of the portal pressure, thus

preventing the acute portal hypertension and thetendency to haemorrhages.


7/29

2). Haematological functions: a).Site of hematopoyesis: -Through the red pulpit produces and releases

monocites. -Through the white pulpit produces lymphocytes and

plasma cells. During the intrauterine period the spleen plays an important

role in hematopoyesis. This situation ends at birth, but maypathologically reappear as extramedulary hematopoyesis inhaemolytic anaemia, Rh incompatibility or chronic myeloid

leukaemia. b).Site for hemolysis:nowadays the spleen is not seen as

a cemetery for old red cells any more. Normal hemolysistakes place 50% in bone marrow and 50% in the liver andspleen (25% each).

The spleen seems to play a role in controlling the finishing

of the erythrocytes, thats probably why in the spleenagenesy or after splenectomy, various abnormalities of theerythrocytes are found: the Jolly corpuscles (nuclearremains), siderocytes (erythrocytes containinghemosiderine granules), Heinzs corpuscles (degraded Hb),etc.


8/29

c).The spleen and the Platelets:after about 10days in circulation, the thrombocytes aredestroyed inside the spleen. The spleen normally

contains one third of the total platelets, but thisproportion may increase up to 90% during ahypersplenic state. That explains why aftersplenectomy an increased platelet number is foundin the circulating blood.

d).The spleen and blood clotting: -Storage of platelets and of the VIII clotting

factor -Clearance of the tromboplastine and fibrin

complexes


9/29

3). The spleen and the Immune Defences:Thespleens role in immunity is proved by theincreased vulnerability to infections during the

first year after splenectomy or after splenectomyperformed under 5 years of age. a)Fagocytosis:is based on the spleens richness

in R-H tissue. The spleen phagocytes are the endothelial cells

from the walls of the sinuses and the reticularcells from the Billroths cords, either fixed ormobile. Thus, the spleen tissue becomes a filterable to filtrate bacteria, parasites, cancerouscells, abnormal erythrocytes, colloidal and lipidicsubstances.

It seems that during the first month of life thespleen R-H tissue is likely to be only tissue able tofagocitate foreign particles, since no naturalantibodies is yet present.


10/29

b).Production of Antibodies:the spleen is alymphoid organ.

The spleen, like the lymph nodes, are the

peripherallymphoid tissue. Since the spleen is located on the blood circulation,while the lymph nodes are located on the lymphcirculation, a difference in quality and quantity intheir immune functions is found.

-Quantity:the spleen permanently contains a bigamount of lymphocites. The lymphopenia found after radiation of the

spleen is more important than the one found afterdrainage of the thoracic duct.

-Quality:the spleen does not have afferentlymphatic vessels, so it can be stimulated only bycirculating antigens.


11/29

The humoral response may be primary (IgMproduction) or secondary (IgG production).

The increased vulnerability to infections after

splenectomy (more evident in children as in adultindividuals) may be explained by the long lastingalterations of the primary response to intravenousimmunization, by the decreased IgM level duringthe first 6 month after splenectomy, and also bythe loss of an important fagocitating organ.

4). The metabolic functions of the spleen. The spleen participates to the metabolism of

water, calcium, potasium, lipides and proteins.


12/29

The hypersplenismis a controversial issue. For its understanding several hypotheses are discussed: a).Hyperplasia of histiocitar cells with an increased

capability of fagocitation;

b).The presence of a spleen hormone which may inhibit thebone-marrow cell production and maturation, leading tomedular aplasia.

c).Spleen production of specific antibodies directed againstblood cells and bone-marrow hematopoyetic cells. In this way,these cells become more fragile and can be retained and

destroyed in the spleen much easier. This explanation seemsto be the most accepted one. The hypersplenic syndromeassociates: -anaemia, neutropenia, thrombocitopenia, isolated or

associated; the reticulocyte number is variable; -normal or hypercellular aspects of the bone marrow;

-splenomegaly; -the blood formula comes back to normal after splenectomy.


13/29

EXPLORATION OF THE SPLEEN Clinical findings: - Inspection:only a huge spleen enlargement is able to swell

the left hemithorax, the left hypocondrium and the middle

abdomen; - Palpationis the most important exam. It can be performedeither with the patient laying on his back or laying on hisright side. Are to be apreciated:- sensibility

-consistency:-hard: sarcomas, leukemias -soft : infectious disease

-surface: normally smooth having front edgewinding, may become irregular in tumors, leukemias,

hydatidosis -mobility: the spleen normally lowers with

inspiration.

In newborn and small child, the normal spleen is palpable in upto 10% of the cases.


14/29

Hackett states five degrees of spleenenlargement (accepted by WHO):

1st degree: palpable spleen during a profound

inspiration; 2nd degre: the spleen does not pass below ahorizontal line drawn at half distance between theumbilicus and the lowest rib edge;

3rd degree: the spleen passes below this line;

4th degree: between the umbilicus and thehorizontal line drawn at half distance between theumbilicus and the pubis;

5th degree: it passes below this last line. - Percussion:not suitable for children;

- Hearing:a vascular noise may be heard in case ofaneurism of one of the spleen arteries;


15/29

The splenomegaly is to bedifferenciated from: 1.Chest or abdominal walls tumours (such tumours

move along with the wall during contraction; 2.A hypertrophic left lobe of the liver; 3.Left kidney hydronephrosis or tumour; 4.Adrenal gland tumour; 5.Tumour of the stomach, of the colon; 6.End of pancreas tumour;

7.Mezentheric tumour; 8.Gigant ovarian tumour.


16/29

Laboratory findings: 1.Hematologic findings: .erythrocyte counting .leukocyte counting and formula .thrombocyte counting .reticulocyte . Globular osmotic resistance of erythrocites . Electroforesis of Hb . The bone marrow aspect and cellularity . The bilirubin levels: either free or combined

. The seric iron level . Erythrocytar G6PD level 2.Blood culture 3.The serology of the blood 4.Hepatic tests

5.Intradermoreactions with tuberculin and other antigenes


17/29

6.Radiology findings: . simple radiography or after insuflation of air in the

perithoneal cavity . splenoportography . selective arteriography 7.Ultrasonography 8.CT scan 9.MRI 10.Puncture of the spleen: it normally contains: Ly=60-80%

H=20-30% G=10% 11.Limph node, liver and marrow puncture or biopsy 12.Scintigraphy-with radioactive gold 198 -after introduction in circulation of E

marqued with radioactive 51 chromium


18/29

Splenomegaly may be:

- isolated

- associated with:

- hepatomegaly

- fever

- adenomegaly

- hematological disorders


19/29

Differential Diagnosis of Splenomegaly byPathophysiology

after Susan B. Shurin and Kelly W. Maloney I. Anatomic lesions: - Cysts, pseudocysts - Hemangiomas and lymphangiomas

- Hematoma or rupture ( traumatic ) II. Hyperplasia caused by Hematologic Disorders a) Acute and Chronic Hemolysis - Hemoglobinopathies

- Erythrocyte membrane disorders - Erythrocyte enzyme deficiences - Immune hemolysis - Paroxysmal nocturnal hemoglobinuria


20/29

b) Chronic Iron Deficiency c) Extramedullary Hematopoiesis

- Severe hemolytic anemias

- Myeloproliferative diseases: chronic

myelogenous leukemia ( CML ), juvenile CML,myelofibrosis with myeloid metaplasia,polycythemia vera

- Osteopetrosis


21/29

III. Infections

a) Bacterial

- Acute sepsis: Salmonella typhi,Streptoccocus pneumoniae, Haemophilus infl. Type

b, Staphyloccocus aureus. - Chronic infections: infective endocarditis,

chronic meningococcemia, brucellosis, tularemia,cat-scratch disease

- Local infections: splenic abscess, pyogenicliver abscess, cholangitis


22/29


23/29

c) Spirochetal

- Syphilis, especially congenital syphilis

- Lyme disease

- Leptospirosis

d) Rickettsial

- Q fever - Typhus

e) Fungal / Mycobacterial

- Miliary tuberculosis

- Disseminated histoplasmosis - Systemic candidiasis ( in immunosuppressed

patients )


24/29

f) Parasitic

- Malaria

- Toxoplasmosis, especially congenital

- Toxocara canis, toxocara cati ( Visceral

larva migrans ) - Leishmaniasis ( Kala-Azar )

- Schistosomiasis

- Trypanosomias

- Fascioliasis


25/29

IV. Immunologic and Inflammatory Processes

- Colagen vascular diseases

- Systemic lupus erythematosus

- Rheumatoid arthritis

- Mixed connective tissue disease

- Systemic vasculitis - Serum sickness

- Drug hypersensitivity, especially tophenytoin

- Sjgren syndrome - Cryoglobulinemia


26/29

- Amyloidosis

- Inflammatory bowel disease

- Myasthenia gravis

- Sarcoidosis - Histiocytosis syndromes

- Graves disease

- Hashimoto thyroiditis


27/29

V. Malignancies

a) Primary

- leukemia ( acute, chronic )

- lymphoma - angiosarcoma

- Hodgkin disease

b) Metastatic


28/29

VI. Storage Diseases

- Lipidosis ( Gaucher disease, Niemann-Pickdisease )

- Mucopolysaccharidoses ( Hurler, Hunter-type )

- Mucolipidosis

- Defects in carbohydrate metabolism (galactosemia, fructose intolerance )

- Sea-blue histiocyte syndrome

- Amyloidosis


29/29

VII. Congestive

- Congestive heart failure

- Intrahepatic cirrhosis

- Extrahepatic portal splenic, and hepaticvein obstruction ( thrombosis, Budd-Chiarisyndrome ).

the splenomegaly power point dr. cosmescu

Documents