What is splenomegaly?

What is splenomegaly?

An abnormal enlargement of the spleen (splenomegaly) can have different possible causes. What does this symptom mean? Who to consult? Explanations from Dr Juliette Soret-Dulphy, hematologist at AP-HP.

Located below the diaphragm, in the upper left part of the abdomen, the spleen is part of the immune system and performs several important functions. “In addition to its function of protection against infections, the spleen plays a filter role, eliminating used red blood cells. It also stores a large part of platelets and plays a role in regulating blood flow,” underlines Dr Juliette Soret-Dulphy, hematologist at AP-HP.

Whatever the cause, an increase in the volume of the spleen is always abnormal and should be the subject of a consultation. It is not a pathology in itself but a symptom that must be taken into consideration. “When the size of the spleen is normal, a doctor should not feel this organ on palpation during a clinical examination. continues the specialist.

Splenomegaly may have no symptoms

An enlargement of the spleen is not necessarily painful. “The patient can sometimes feel a bothersome sensation of compression or heaviness in the abdomen, mainly after meals, sometimes real pain, or have no particular sensation. specifies the hematologist.

When the problem persists for some time without being diagnosed, digestive problems (bloating, constipation) may also be present. As the increase in the volume of the spleen is not necessarily painful, the discovery of splenomegaly may be fortuitous, during a clinical or radiological examination.

Splenomegaly can have different causes and occur in very different medical contexts. Treatment can therefore only be considered once the diagnosis has been established and the responsible cause has been clarified.

The different possible causes of splenomegaly

Viral diseases and infections

An enlarged spleen can be caused by a bacterial, viral or parasitic infection. This can be seen in the context of sepsis or other bacterial infections. It can also be a virus such as infectious mononucleosis, HIV or certain hepatitis. On the parasitic side, malaria or leishmaniasis can also be responsible for splenomegaly. “If the cause is transient, splenomegaly has no impact. The spleen will return to its normal size once the infection resolves.”, explains the doctor. Care by the treating physician or infectious disease specialist is therefore required.

Genetic diseases

Certain genetic diseases can cause an abnormal enlargement of the spleen. This is the case for certain hematological diseases, linked to abnormalities of the red blood cell membranes, such as hereditary spherocytosis, or sickle cell anemia, for example. Gaucher disease is another example of a rare genetic disease, part of the so-called “overload” diseases which cause, in the vast majority of cases, splenomegaly. Depending on the specificity of the genetic disease, certain treatments may be considered.

Vascular causes and liver diseases

Abnormal enlargement of the spleen can also be caused by a problem of portal hypertension. Portal hypertension is characterized by an increase in blood pressure in the vein of the portal system, which carries blood from the intestines to the liver, thereby causing an obstruction to the flow of blood. “In Europe, in the vast majority of cases, a portal hypertension problem is due to alcoholic cirrhosis,” explains the hematologist. But there are other causes of portal hypertension, such as portal thrombosis. A complete liver test is systematic in the assessment of splenomegaly. A consultation with a gastroenterologist or hepatologist will be considered to manage the disease responsible for portal hypertension.

Hematological diseases

Splenomegaly can also be a sign of a more or less serious acute or chronic hematological disease. “It can be a symptom of a non-cancerous disease such as hemolysis, or cancerous, such as lymphoma, leukemia or myeloid splenomegaly (also called primary myelofibrosis).

A clinical examination and a blood count must be systematically carried out to allow an initial orientation. A consultation with a hematologist as well as in-depth examinations can then make it possible to establish the diagnosis and consider the appropriate treatment.

If hematological disease is suspected, observation of the lymph nodes is essential. In hematology, certain blood tests can help establish the diagnosis. “The complete blood count (CBC) allows us to check for the presence of anemia, as well as the proliferation of normal or abnormal cells which may be a sign of a malignant hematological disease. continues Dr Juliette Soret-Dulphy.

The management of splenomegaly will therefore be very different depending on the context. An abnormal increase in the volume of the spleen will not have at all the same impact if it is sepsis (this symptom is then of less importance) or a potentially serious hematological disease.

Upon discovery of splenomegaly, questioning (search for fever or recent infection, notion of new fatigue, known liver disease, etc.), clinical examination (in particular palpation of the lymph nodes), prescription of biological tests (CBC, liver test, other tests, etc.) are the first steps that will guide treatment.

Functional or anatomical asplenia

In the event of rupture of the spleen (during trauma, for example) or in certain rare hematological diseases, it happens that a splenectomy, that is to say the removal of the spleen, be considered. This surgical intervention is not without consequences insofar as the spleen plays an important role in the body’s immune defense against infections.

Likewise, if the doctor observes, through a blood smear, that the spleen is no longer functioning (functional asplenia), special precautions must be taken with these patients regarding their immunity to infections. “These patients must be vaccinated against pneumococcal infections, meningococcal infections, Haemophilus influenzae type b infections as well as influenza. underlines Dr Juliette Soret-Dulphy. Indeed, in the absence of an appropriate immune response, these infections could be lethal within a few hours in these patients who become asplenic.

Furthermore, after a splenectomy, daily antibiotic therapy must be initiated for at least two years (and until adolescence if it is a child).

Finally, in the event of infection, antibiotic therapy must be initiated urgently and continued over the long term.