D37-D48: Neoplasms of uncertain or unknown behaviour

D47: Other neoplasms of uncertain or unknown behaviour of lymphoid, haematopoietic and related tissue

The conditions grouped under the D47 label represent a range of disorders characterized by the abnormal growth of cells within the lymphoid, haematopoietic, and related tissues. These tissues are vital parts of the body's immune and blood production system, residing primarily in the lymph nodes, spleen, and bone marrow. Despite being classified as "neoplasms", the cells in these conditions don't behave typically like cancerous cells and hence, are said to possess "uncertain or unknown" behaviour. Symptoms vary based on the tissue type and location of the abnormal growth, but may include fatigue, unexplained weight loss, excessive sweating, fever, or enlarged lymph nodes. Progression of these diseases also ranges, with some remaining stable for years while others may transform into more aggressive disorders. To reiterate, these conditions typically involve the growth of abnormal cells within parts of the body responsible for immunity and blood production.