Organ of the Month: Spleen

The gold standard way to sample the spleen following splenectomy is NOT to sample.  Submitting the entire spleen is more likely to lead to a definitive diagnosis than even multiple sections². Our fact sheets on splenic sampling and submission of whole organs provide more details^3,4.  It is best to fix the entire spleen at your practice in a large bucket that allows the entire spleen to be submerged in 10% neutral buffered formalin (NBF). After about 3-4 days, the spleen can be sent in a smaller volume of formalin, wrapped in gauze or paper towels pre-soaked in 10% NBF, then double bagged and, ideally, placed in a protective container.  Prior to fixation, a series of partial incisions made through the capsule will allow better formalin penetration.  Please bear in mind that spleen is an organ that often takes longer to fix and it may still require a more prolonged fixation time, even after arriving at the laboratory. This is mainly due to its high blood content. 

If sending the entire organ is not feasible, then submission of selected, representative sections is the next best option, ideally supported by annotated photographs. When sampling nodules, we strongly advise sampling of the transition area between the nodule and the surrounding spleen.  Sampling the centre is likely to capture only blood and may miss more diagnostic peripheral tissue, particularly in haemangiosarcoma (see Fig 1).