Different morphology of megakaryocytes to help and guide to diagnosis


Normal megakaryocytes features:

Normal megakaryocytes:
Strongly multi-lobulated nucleus with irregular lobes, connected with chromatin threads, with a clumped chromatin structure. Cytoplasma can be anything from basophilic to pink and can contain from none to abundant azurophilic granules

Myelodysplastic features (MDS):

mononuclear cell
12-40 µm diameter, sometimes bilobulated, dense chromatin with high nucleas to cytoplasm ratio. Cytoplasm is moderately mature
normal sized megakaryocyte with hypo- or non-lobulated nucleus,
rond to oval shaped, normal chromatin condensation and normal cytoplasm structure.
normal to large megakaryocyte with multiple separate nuclei,
usually rond, normal to dense chromatin condensation and normal cytoplasm structure.

Features with different Myeloproliferative disorders (MPN):

Increased number of smaller megakaryocytes and sometimes hypolobulated.
Increased number of morphologically normal megakaryocytes, in all different maturation stages. Often clustering.
Many megakaryocyten in normocellulair bonemarrow, with bizarre giant megakaryocytes, with abundant cytoplasm and hyperlobulated nucleus (stag-horn shaped) and clumped chromatin.

Cells that may mimic megakaryocytes

Large cells, have multinucleated, well-separated and uniformly sized round to ovoid nuclei.
Multilobulated giant plasmacells
Morbus Hodgkin:
Hodgkin cells: large multilobulated nucleus with coarse chromatin, multiple bluish nucleoli, abundant slightly basophilic cytoplasm.