Wright stain: 看eos, basophils

Liu stain: 看myeloblast

低倍：

Cellularity: 100 - age

Megakaryocyte numbers: 4~10 or 5-15/ LPF，超過10-15個過多

Normal M:E ratio 3-5:1

Dysplasia定義：單一lineage超過10%

Mega: 超過30顆中>10% dysplasia，或>30-40% dysplasia

Erythroid

Normoblast: 細胞膜周圍一圈深藍色，細胞核深淺不一，可能會有budding

Schematic diagram of erythroid precursor development. The proerythroblast is the first identifiable erythrocyte precursor by light microscopy. The cell has a very high nuclear:cytoplasmic ratio. A nucleolus is usually evident. The cytoplasm is basophilic but often not as deeply so as the basophilic erythroblast and a light area shaped as a crescent is usually paranuclear. The basophilic erythroblast is a bit smaller than its precursor and the cytoplasm is often more intensely blue with a diminution or absence of the lighter staining crescent-shaped paranuclear zone. A nucleolus may be evident. The polychromatic erythroblast is a smaller cell than its precursor and has a light blue-gray cytoplasm because of the onset of hemoglobin synthesis. The eosinophilia of hemoglobin mixing with the basophilia of the ribosomes and other organelles results in the gray-blue consensus color. The orthochromatic erythroblast is smaller, on average, than its precursor and has a more eosinophilic colored cytoplasm. Throughout the last two steps, the nucleus gains more heterochromatin and euchromatin is less prominent. Nucleoli have disappeared from late polychromatophilic and orthochromic erythroblasts. After enucleation, the polychromatic erythrocyte is formed: anucleate but with residual ribosomes taking the basophilic elements of the polychrome stain resulting in a consensus pale blue-gray cytoplasmic color. If stained with a supravital dye, such as new methylene blue, the characteristic beaded precipitates of ribosomal chains are evident. This stained cell is referred to as a reticulocyte. After release into the circulation, the residual basophilic staining organelles are degraded by intraerythrocytic enzymes, resulting in the reddish-orange colored erythrocyte.

Erythroid precursor sequence. Light microscopic appearance. Human marrow films stained with Wright stain. The five stages of erythroblast development recognizable by light microscopy are (A) Proerythroblasts. Two are present in this field. They are the largest red cell precursor, with a fine nuclear chromatin pattern, nucleoli, basophilic cytoplasm and often a clear area at the site of the Golgi apparatus. (B) Basophilic erythroblast. The cell is smaller than the proerythroblast, the nuclear chromatin is slightly more condensed and cytoplasmic is basophilic. (C) Polychromatophilic erythroblasts. The cell is smaller on average than its precursors. The nuclear chromatin is more condensed with a checkerboard pattern developing. Nucleoli are not apparent, usually. The cytoplasm is gray reflecting the staining modulation induced by hemoglobin synthesis, which adds cytoplasmic content that takes an eosinophilic stain, admixed with the residual basophilia of the fading protein synthetic apparatus. (D) Orthochromatic erythroblast. Smaller on average than its precursor. Increasing condensation of nuclear chromatin. A homogenous cytoplasmic coloration approaching that of a red cell. (E) Late orthochromatic erythroblasts (asterisks). The orthochromatic erythroblast to the right is undergoing apparent enucleation. The other three mononuclear cells are lymphocytes. A degenerating four-lobed neutrophil is also present.

Erythroid island

Characteristic central macrophage surrounded by erythroblasts. This structural appearance has given the impression of the macrophage having a nursing function. The attachment is mediated by a specific receptor-ligand interaction.