Corpus: Splenomegaly

The term splenomegaly refers to an enlargement of the spleen.

The spleen is approx. 11 cm long, 7 cm wide (transverse diameter) and 4 cm thick. Depending on the blood volume of the individual, the organ weight averages 160 g when the organ is completely bled. The size of the spleen can be reliably determined by spleen sonography.

Enlargement of the spleen can have various causes:

Disturbed blood outflow[Bearbeiten]

• Splenic vein thrombosis
• Budd-Chiari syndrome
• Liver cirrhosis
• Portal vein hypertension
• Right heart failure

Infectious causes[Bearbeiten]

• Infectious mononucleosis
• Tuberculosis
• Malaria
• HIV
• Viral hepatitis
• Leishmaniasis
• Echinococcosis

Infiltrative causes[Bearbeiten]

• Extramedullary haematopoiesis
• Neoplasms:
  • Leukaemias
  • Lymphomas, Hodgkin's disease
  • Myeloproliferative syndromes (primary myelofibrosis, polycythaemia vera)
• Amyloidosis
• Gaucher's disease
• Niemann-Pick disease
• Hurler's disease

Immunopathies[Bearbeiten]

• Rheumatoid arthritis (Felty syndrome)
• Systemic lupus erythematosus
• Autoimmune haemolytic anaemia

Erythrocytic structural defects[Bearbeiten]

• Spherocytosis
• Thalassaemia

Haemoglobinopathies[Bearbeiten]

• Sickle cell anaemia

Other causes[Bearbeiten]

• Thyrotoxicosis
• Iron deficiency anaemia
• Berylliosis

The extent of splenomegaly can be used to differentiate between mild, moderate and massive forms of splenomegaly.

Mild splenomegaly[Bearbeiten]

Mild splenomegaly is characterised by an organ weight of less than 500 g. Common causes are bacterial inflammation or febrile infections.

Moderate splenomegaly[Bearbeiten]

The organ weight is between 500 and 800 g. This occurs, among other things, in chronic congestion of the spleen, haemoglobinopathies and storage diseases.

Massive splenomegaly[Bearbeiten]

Massive or extreme splenomegaly is characterised by an organ weight of over 1,000 g. The spleen is up to 8,000 g in weight. The spleen can be palpated up to 8 cm below the costal arch. Such a pronounced enlargement of the spleen is found in chronic myeloproliferative diseases such as CML, polycythaemia vera, osteomyelofibrosis or lymphomas. Other possible causes include Gaucher's disease, thalassaemia major, malaria or visceral leishmaniasis.

Alternative categorisation[Bearbeiten]

According to Poulin, the extent of splenomegaly is based on the largest organ diameter.^[1] The following applies:

• Normal findings: < 11 cm
• Moderate splenomegaly: 11-20 cm
• Severe splenomegaly: > 20 cm

Mild splenomegaly is asymptomatic. A more pronounced increase in the volume of the organ can lead to nausea, a feeling of fullness or abdominal pain in the left upper abdomen by displacing the neighbouring organs.

The suspected diagnosis of splenomegaly can be made clinically by palpation or percussion. On deep inspiration, a slightly enlarged spleen touches the examiner's fingertips. In slender patients, a non-enlarged spleen can also be perceived in some cases. If the enlargement is more pronounced, the caudal edge of the spleen can be felt under the costal arch.

The diagnosis is confirmed by imaging procedures such as sonography, MRI or CT. The internal structure of the spleen can also be analysed, which provides further differential diagnostic clues.

Hypersplenism can occur as a complication of splenomegaly. Spontaneous rupture of the spleen can also occur due to overstretching of the spleen capsule.

Splenomegaly is a concomitant symptom, not an independent disease. Treatment therefore depends on the triggering cause.