This case was focussed on the investigation of splenomegaly, rather than the ultimate diagnosis (though we did make one). So what did we learn?
This varies, but 14cm is generally considered to be the upper limit of normal.
See case update 1 here for a pretty comprehensive differential list, or here for the tables in Essential Haematology textbook. Many can be excluded with a thorough history, but clearly further investigations are usually required.
Here are some points to consider when investigating splenomegaly.
This rarely provides a diagnosis in itself, as there are no features that are likely to be sufficiently specific. However other features seen on scans may provide very useful pointers, such as liver fibrosis, or the presence of lymph nodes.
BONE MARROW BIOPSY
Many conditions that cause splenomegaly may be detected on BM biopsy, as both are part of the reticuloendothelial system.
Systemic disorders that may be detected on BM biopsy include sarcoidosis, amyloidosis and Gaucher’s disease.
Haematological disorders that can readily be detected by marrow include myeloproliferative neoplasms and lymphoproliferative disorders.
Infections that cause splenomegaly can usually be detected in the marrow and include:
- leishmaniasis (see our earlier case)
As haematologists we rarely organise splenic biopsies, as the conditions in which we are most interested tend to co-exist in the marrow and spleen. However it is possible for marrows to be non-diagnostic, or non-haematological diagnoses to make a splenic biopsy a more appropriate investigation.
FNA may be appropriate in some situations, but core biopsies are likely to be needed in many patients. The published data on splenic biopsy safety is limited, but the papers that exist suggest it is a reasonably safe investigation. Of course this is relative, and in many situations a watch and wait policy is probably preferable: a 10% bleed risk is not acceptable in an entirely asymptomatic patient with a normal full blood count. However, where the risk is considered acceptable, splenic biopsy results in tissue sufficient for diagnosis and subtyping of lymphoma in 90% of cases.
Data on diagnostic splenectomy largely predates more modern surgical techniques (Hand assisted laparoscopy being now commonly used, particularly if diagnostic samples are needed) and likely overestimates current morbidity and mortality. However all historic studies suggest the larger the spleen the higher the risk of complication, and this must be considered when opting for surgery. In addition the long term risk of overwhelming sepsis in splenectomy is well established and carries a 1% mortality rate – see the now archived BCSH guideline for more details.
There are some patients in whom splenectomy is beneficial in itself – for those with severe cytopenias of any cause, in patients with primary splenic lymphoma, or in patients symptomatic of their enlarged spleen. For the remaining majority a ‘watch and wait’ approach is likely to a safer approach than splenectomy, given that not every patient with splenomegaly ever develops disease.
Our patient did indeed have Hairy Cell Leukaemia, as correctly identified by many of you. This has been covered by Teamhaem before in case 12.
Thank you for reading. Keep following us @teamhaem for further cases and news relating to haematology.
References (other than provided links)
Pozo et al (2009). Splenomegaly: Investigation, diagnosis and management. Blood Reviews 23, 105-111.