This case was an interesting one! As haematologists we have a privileged position of being able to get to know our patients extremely well and also have the skills to review their marrow under the microscope in order to reach a diagnosis. Usually we will have an idea of what we expect to find and sometimes we will not. It is important we keep an open mind when reviewing a patient’s material. In this case we were expecting to find relapsed disease or perhaps secondary AML/MDS related to previous therapy for non-Hodgkin lymphoma. In fact we found leishmaniasis!
This is a parasitic disorder caused by a protozoan of the genus Leishmania. There are three main clinical forms of the disease:
- cutaneous – skin involvement
- mucocutaneous – skin plus mucus membranes
- visceral – disseminated
It is spread by a sandfly and the most common affected areas are the Mediterranean, India, Bangladesh, Brazil and parts of Africa. In immune compromised patients it is common to have a lack of an ‘exotic’ travel history.
In visceral leishmaniasis symptoms can be similar to that of newly diagnosed lymphoma:
- Night sweats
- Weight loss, anorexia
- Dark pigmentation of the skin
Full work up of any patient with the above symptoms would include: FBC, renal and liver function, bone profile, CRP/ESR, immunoglobulins, B12/folate, HIV, hepatitis viruses, blood cultures and examination of the peripheral blood to include appropriate malaria staining. The cornerstone to diagnosing leishmaniasis is to obtain tissue – whether this be through skin biopsy, bone marrow biopsy, lymphoma node or splenic biopsy. Bone marrow is frequently used as it is probably safer than splenic biopsy. Leishmania amastigotes can be viewed microscopically as in our case. Cultures can be taken as well as serological and PCR studies.
This depends on a number of factors but can include amphotericin, miltefosine or pentamidine.
Haematology and infectious diseases
Haematological abnormalities is a common problem in infectious diseases. The inflammatory response can produce abnormal proliferation of cells (e.g. neutrophilia in response to infection) and less commonly pancytopenia due to toxic effect on the marrow or an immune-mediated cause. Frequently viral infections, especially in children, can result in neutropenia. This can further be exacerbated by toxic effects of medications on the marrow as well as liver injury.
When there is a history of acute infection and subsequent pancytopenia with a recently normal full blood count it would be uncommon for the pancytopenia to be due to a primary haematological cause. If there are no other worrying signs to point towards haematological malignancy a ‘watch and wait’ approach can generally be employed. Most cytopenias will improve as infection resolves.
Occasionally bone marrow biopsy is needed when there is not improvement, if haematological malignancy is suspected from the history or blood film or in the immune compromised patient.