Monday, 1 November 2010

MRCP revision battle 39.6: The spleen

My dubious relationship with the spleen goes waaayyy back to medical school anatomy days when I learnt that any mass of tissue that I had absolutely no idea what it was when placed on a tray in front of me was usually a spleen.

The spleen was equally mysterious to the medical profession in general for many years, as no-one was quite sure as to its function.  It is now known to act as a reservoir for lymphocytes and so is vital in dealing with bacteraemias.

This battle will look at the 2 extremes of spleen: splenomegaly, and hyposplenism/post splenectomy.


Massive splenomegaly can occur in:
  • CML
  • myelofibrosis
  • malaria
  • leishmaniasis
  • Gaucher's syndrome (= an inherited lysosomal storage disease)

Moderate splenomegaly can occur in:
  • infections: typhoid, brucella, TB, glandular fever, EBV, schistosomiasis
  • haematological disorders: lymphoma, leukaemia, haemolytic anaemia
  • connective tissue disease: SLE, RA
  • portal hypertension: cirrhosis, CCF


Splenectomy is performed for a variety of reasons including:
  • trauna
  • ITP
  • warm AIHA

2 weeks prior to splenectomy pneumoccal vaccine and HiB should be given; if the splenectomy is an emergency these should be given ASAP afterwards.
Lifelong penicillin (or erythromycin if penicillin allergic) is then also needed.

Most common serious infections after splenectomy are from encapsulated organisms such as s.pneumoniae, h.influenzae and n.meningitidis.

Blood film after splenectomy shows:
  • Howell-Jolly bodies (=nuclear remnants in RBCs)
  • target cells
  • Pappenheimer bodies (=abnormal iron inside RBCs)

There is low IgM.

As well as hyposplenism being a problem post splenectomy, it can also occur in sickle cell disease, coeliac disease and myeloproliferative diseases

Now onwards to some AIHA...