Question 25 from the first paper of 2005 asked the candidates to arrive at a series of sensible differentials to explain a case of pancytopenia in a 68 year old man with diffuse bilateral pulmonary infiltrates. Question 23.3 from the second paper of 2015 examines the cause of a pancytopenia in a patient with multi-organ system failure in the context of pneumonia and sepsis.

Readable literature for this topic needs to include the following sources:

• Kufe et al (2003) on the oncological causes of pancytopenia
• Weinzierl et al (2013) for a list of (many) other causes

These have been condensed into the table offered below:

Bone marrow biopsy is the investigation of choice for pancytopenia.

It will rapidly narrow the list of differentials, at least if one is able to catch some cells in one's sample. Occasionally, one finds a pocket of totally acellular marrow, which - though ominously prognostic - is frequently useless diagnostically.  The most likely cause of pancytopenia is acute lymphoblastic leukaemia in children and acute myeloid leukaemia/myelodysplastic syndrome in adults.