Abnormal cells derived from bone marrow which originated cells that would normally develop into erythrocytes, granulocytes, monocytes or megakaryocytes. Three broad clinicopathologic classes:

Acute Myeloid Leukaemia’s (AMLs):

Cancer of the blood and bone marrow and defined by a 20% overproduction of myeloid blasts in the bone marrow or peripheral blood.

Myeloproliferative Neoplasms (MPNs):

Abnormal cells that affect the normal production of blood cells in the bone marrow causing the proliferation of one or more of blood cell types.


Rare mast cell disorder characterised by the build-up of pathologic mast cells in tissues. This can occur in the skin, bone marrow and internal organs. In most cases, this is associated with changes in the KIT gene.



A group of disorders that present dysplasia (or the presence of abnormal cell types) and disruption to the normal production of blood cells.

In some instances, features of MPN and MDS may overlap and all MPN and MDS can potentially develop into AML.

Lymphoid Neoplasms:

Abnormal cells that originate from B- and T-cells (bone marrow derived or thymus derived), and B- and T-lymphocytes. In the past, neoplasms present in the bone marrow and blood were segregated from those which presented as a mass. Lymphoid neoplasms are categorised based on whether they are of B, T, or natural killer (NK) cell derivation.

Histiocytic/Dendritic Neoplasms:

These neoplasms are very rare haematological disorders and originate from cells that would normally develop into dendritic cells or histiocytes.