MS-2757

A 16-year-old boy has been diagnosed with aplastic anaemia. He hails from a family of farmers and used to play hide and seek in the barns where pesticides and other chemicals were stored. He visited his GP complaining of fatigue, dyspnoea, and headaches. Further blood tests revealed a significant leucopenia. Aplastic anaemia is a condition where haematopoietic stem cells that produce immune cell precursors fail. Where in the body are these cells primarily located?