Splenomegaly

Basics

DESCRIPTION

  • Splenomegaly can be an incidental finding on imaging or examination or it can present with left upper quadrant pain.
  • Thorough history often can differentiate the various causes of splenomegaly.
  • Normal spleen sizes correlate with height and age. It can range from 5 cm in a newborn to >13 cm for adolescents.
  • A palpable spleen is found in most premature infants and in 30% of term infants. A spleen tip is still palpable in 10% of infants at 1 year of age and in 1% of children at 10 years of age.
  • The clinical significance of splenomegaly found on a radiologic study but not palpable on physical exam is unclear in the absence of other laboratory or clinical data.

PATHOPHYSIOLOGY

  • The spleen is a hematopoietic organ with two main parts:
    • White pulp is the lymphoid tissue.
    • Red pulp is the red cell mass.
  • Splenic sinusoids are lined with macrophages that destroy abnormal red cells and other cells or opsonized bacteria that need to be removed from the circulation.
  • The lymphoid function of the spleen makes up about 25% of the lymph tissue of the body.
  • The spleen also serves as a reservoir for platelets. A normal-sized spleen can hold 1/3 of the circulating platelets; an enlarged spleen can hold up to 90% of the circulating platelet mass.

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