What is the cause of the appearance of the spleen?
Patchy regions of splenic infarction.
What are some of the underlying diseases you would consider in this patient?
Knowing that they have a haematological disease, narrows the list down to conditions which lead to splenomegaly and infarction; unfortunately this includes many conditions, including: anaemias (sickle cell disease (classical and most common in some demographics), thalassaemia, hereditary spherocytosis, pyruvate kinase deficiency, thrombotic thrombocytopaenic purpura (TTP)) and neoplastic / proliferative disorders (e.g. leukaemia, polycythaemia rubra vera (PRV) etc...).
This patient has known sickle cell disease. What is the likely long term outcome for this patients spleen?
Repeated episodes of infarction, gradually obliterate the spleen, leaving behind a tiny, sometimes calcified, remnant. This is termed 'autosplenectomy'.
Briefly describe the underlying pathology of sickle cell disease.
The term "sickle cell disease" applies to all patients who have two abnormal haemoglobin beta chains. The resultant haemoglobin molecules tend to clump together into long polymers, making the red blood cell elongated (sickle shaped), rigid and unable to deform appropriately when passing though small vessels, resulting in vascular occlusion. Individuals with one HbS beta chain and one normal beta chain are said to have the "sickle cell trait", and are usually asymptomatic.
Pre and post contrast axial images through the abdomen demonstrate the spleen to be enlarged and heterogeneous in density with numerous areas of low density which do not enhance.
The spleen is enlarged, but no enlarged lymph nodes are visible. The liver appears enlarged, but is otherwise normal. Patchy dependent lung changes are present, more so on the right.