Bone Marrow Lab

• myeloblast
• promyelocyte
• myelocyte
• band
• mature granulocyte

myelocyte - small cell, nucleus is round to oval, nucleus often eccentric, 1:1 ratio nucleus:cytoplasm

• adipose cell
• myelocyte (has no nucleolus)
• smearing

• from the top, clockwise around...
• myeloblast (nucelolus present), rubricyte, band, metamyelocyte, rubriblast (nucleolus present)

• lighter color cytoplasm than reds
• round nucleus only in blast and progranulocyte stage, then the nucleus indents in the more mature stages

rubriblast - round cell with round nucleus, narrow rim of dark/bright blue cytoplasm, large cell, 1 - 2 nucleoli within nucleus

myeloblast - round/oval nucleus, 1 or more nucleoli, small to moderate amount of blue cytoplasm

• too much back pressure on the syringe or continuing sample collection after the needle hub shows the presence of marrow
• contamination also occurs when a blood filled sinus is encountered while placing the bone marrow needle.

• esoinophilic myelocyte
• eosinophil
• prorubricyte
• rubricyte
• band
• metarubricyte
• metamyelocyte
• myelocyte
• metarubricyte

metamyelocyte

• Metamyelocyte
• nucleus indents, chromatin more condensed, may see granules in cytoplasm, mature into bands

• promyelocyte/progranulocyte
• no nucleolus, perinuclear clear zone, pinkish cytoplasmic granules

• smaller cell
• round nucleus
• coarsely granular chromatin: more condensed
• several types seen - cytoplasm bright to pale blue

• prorubricyte
• similar to rubriblast (except no nucleolus present), lacey (vesicular) chromatin
• perinuclear clear zone

• osteoclast
• large cell
• distinct individual multiple nuclei
• confused with neoplasia or megakaryocytes
• breaks down bone

• osteoblast
• rarely seen in adults, oval/eccentric nucleus with perinuclear clear zone, large amount of cytoplasm, often see nucleoli

• a small round-oval structure within the nucleus of cells.
• contain RNA and protein 
• seen in immature cells
• stains lighter than the surrounding nucleus

• appears with int he nucleus 
• deeply basophilic and sometime nearly black staining
• perimeter is not smooth

age

• young animals 75% cells with 25% fat cells
• mature animals 50% bone marrow cells with 50% fat cells
• geriatric animals 25% cells with 75% fat

adipocytes

• Scan slide on 10x and 40x for large cells and to find the monolayer
• move to oil once you find the monolayer
• count 500 precursor cells including metarubricytes and bands
• include megakaryoctes, plasma cells, osteoclasts, and osteoblasts in your count
• after 500 cell are counted record the total for each series
• calculate the relative differential count and record
• include "other" cells as well as myeloid and erythroid in this differential
• example:  500 total cells counted...20 rubriblasts counted...20/500=0.04...0.04 x 100 = 4%

mature

• size of cell in comparison to a mature cell
• amount and color of cytoplasm
• not if granules or clear areas are present in the cytoplasm
• size and shape of nucleus
• nuclear detail, including presence of nucleoli and chromatin patterns
• note presence or absence of a perinuclear clear zone

iliac crest

trochanteric fossa

granulocytic hyperplasia

• cell production out of control
• immature cells > mature cells
• a type of neoplaisa
• named by cell type involved (may not be able to identify)

• to obtain bone marrow core sample
• used for histology

• lymphoblasts
• large lymphs with nucleolus

• to obtain bone marrow aspirate samples
• used for cytology

• megakaryoblast
• promegakaryocyte
• megakaryocyte

• too much back pressure on the syringe or continuing sample collection after the needle hub shows the presence of marrow
• can also occur when a blood filled sinus is encountered while placing the bone marrow needle

• long, basophilic streaks seen on bone marrow and cytology slides are often due to the destruction of nuclei during preparation
• neoplastic cells often have increased fragility and the nuclei may rupture more easily

• rubricyte
• smaller cell
• round nucleus
• coarsely granular chromatin - more condensed
• cytoplasm bright to pale blue

• plasma cell
• end-stage of B-lymph development
• produce antibodies
• round cell
• round eccentric nucleus
• clumpy chromatin
• perinuclear clear zone

golgi apparatus near nuclear - doesn't take up stain

50% cells, 50% fat

• core biopsy
• bone marrow aspirate

• no RBCs or WBCs
• lack of cell production
• hard to find 500 WBCs + RBCs despite good sample
• best diagnosed on histopathology

immunosuppressive drugs and viruses

• a golden brown-black, granular deposit that is an insoluble form of iron
• increased hemosiderin in the bone marrow may be the result of intravascular hemolysis

• mast cell
• very low numbers in healthy animals
• round cell
• centrally placed nucleus
• small purple granules fill cytoplasm - may obstruct nucleus

• mast cells
• mast cell tumor
• increase in mast cells
• purple cytoplasmic granules may obscure the nucleus

• metarubricyte
• dark nucleus
• smaller cell - almost the size of a mature RBC

eosinophilic myelocyte

eosinophilic metamyelocyte

• large cell
• narrow rim of intensely basophilic cytoplasm
• round nucleus with fine granular chromatin
• 1 - 2 nucleoli

• similar to a rubriblast except...
• nucleoli are no longer visible
• chromatin is coarser/looks lacey
• perinuclear clear zone may be present

• smaller cell with coarse chromatin and more condensed
• round nucleus
• cytoplasm varies from basophilic to reddish-blue depending on amount of hemoglobin

• even smaller cell
• nucleus has become pyknotic (dark, condensed, small) without any light spaces
• nucleus may be eccentric
• cytoplasm is like a polychromatophil

• large, round to irregularly shaped cell
• finely stippled nuclear chromatin/lacey
• one or more prominent nucleoli
• cytoplasm is blue-gray and no granules are present

• large, round to irregularly shaped cell
• more cytoplasm than myeloblast
• nucleus round to oval
• cytoplasm - light blue-gray with scattered, small red/purple granules (primary granules)
• nucleoli are absent or indistinct
• chromatin becoming coarse

• smaller than progranulocyte
• nucleus is usually round, may be beginning to indent
• chromatin beginning to clump
• non specific (azurophlic granules) no longer visible
• definitive (larger) cytoplasmic granules may be visible depending on type of myelocyte
• cytoplasm less basophilic

• similar to myelocyte except...
• cytoplasm clear to slightly granular (except eos and baso)
• nucleus indents to become kidney bean shaped, mitosis no longer occurs
• chromatin coarse with clumps

• large cell
• single nucleus
• deep basophilic cytoplasm

• large cell
• contains 2 - 4 separate or fused nuclei
• basophilic cytoplasm

• gigantic cell
• multiple nuclei joined in a lobed mass
• cytoplasm may be basophilic or violet
• aciophilic cytoplasmic granules may be present

• round, eccentric nucleus with coarse chromatin 
• pale perinuclear clear zone may be present
• large amount of basophilic cytoplasm
• rarely contain round cytoplasmic structures (russell bodies) - if russell bodies are present it is called a Mott cell

• large cell
• may resemble plasma cells except larger and less condensed chromatin
• eccentric round to oval nucleus
• nucleoli may be present
• foamy basophilic cytoplasm
• perinuclear clear zone may be present

• giant cell
• multinucleated, nuclei are distinctly separate
• blue cytoplasm
• cytoplasmic granules

• cell:  size, shape, N:C (use numbers for ratios)
• nucleus:  shape, chromatin pattern (vesicular, lacey, etc), inclusions (nucleolus)
• cytoplasm:  color, perinuclear clear zone