splenomegaly

Coronar

reformatierte Computertomographie einer Patientin mit chronisch lymphatischer Leukämie (CLL). Deutliche Splenomegalie.

Splenomegaly refers to enlargement of the spleen. The upper limit of normal adult splenic length is traditionally cited at 12 cm, but lengths upwards of 14 cm can be seen in normal, taller males .

Massive splenomegaly is variably defined, including when the spleen is 5 standard deviations above the mean normal volume (about 943 cm) , heavier than 1000 g or 1500 g ,longer than 18 cm , or extending into the pelvis or across midline .

Pathology

The causes of splenomegaly are protean, and can be thought of under a number of headings :

hematological disease
hemodynamic
infectious
storage diseases/metabolic/infiltrative disorders
neoplastic (non-hematologic)
traumatic
connective tissue disorders

Hematological disease

anemias
- thalassemia (including beta thalassemia major*)
- sickle cell disease with splenic sequestration (in young patients prior to developing autosplenectomy)
- hereditary spherocytosis
- pyruvate kinase deficiency
- thrombotic thrombocytopenic purpura (TTP)
- Plummer-Vinson syndrome
neoplastic/proliferative/redistribution of hematopoiesis
- myeloproliferative neoplasms*
- acute leukemia*
  - acute myeloid leukemia
  - acute lymphoblastic leukemia
- lymphoma / chronic lymphoid neoplasms*
- extramedullary hematopoiesis
- osteopetrosis
- idiopathic hypereosinophilic syndrome

Hemodynamic

cirrhosis: portal hypertension (common)
congestive splenomegaly (Banti syndrome)
splenic vein obstruction
portal vein obstruction
right heart failure
cystic fibrosis

Infection

viral
- EBV (infectious mononucleosis) (common)
- AIDS with Mycobacterial avium complex infection*
- CMV
- herpes simplex virus
- rubella
bacterial
- tuberculosis (miliary)
- tularemia
- subacute bacterial endocarditis
- typhoid fever
- brucellosis
- syphilis
- abscess
fungal
- histoplasmosis (common)
- candidiasis
parasitic disease
- malaria* (hyperreactive malarial splenomegaly syndrome or tropical splenomegaly syndrome)
- schistosomiasis
- hydatid disease
- leishmaniasis (kala-azar)*
rickettsial
- typhus

Storage diseases/metabolic/infiltrative disorders

Neoplastic (non-hematologic)

Trauma

Connective tissue disorders

* may cause massive splenomegaly

Radiographic features

The shape and orientation of a spleen make accurate linear measurement difficult.

On CT, a splenic width measurement (largest anterior-posterior measurement on axial images) of greater than 10.5 cm is the most accurate single measurement for mild to moderate splenomegaly in patients with cirrhosis; while a craniocaudal measurement of greater than 14.6 cm is the most accurate single measurement for massive splenomegaly .

On sonographic assessment, a length of 12 cm is generally considered the upper limit of normal.