• Implicitly desired information when BM done in:
  1. a new acute leukemic case, initial diagnostic marrow:
     • make a correct diagnosis.
     • give specific percentage cellularity, and
     • percentage blasts.
     • is there any indication of arising out of MDS?
  2. a new acute leukemic, following induction chemo:
     • report clin. info. & diagnosis to recap the leukemic type
     • report clin. info. & diagnosis to state current & prior PB & BM blast percentage.
     • note any presence or absence of chemo effect...
     • opine as to any achievement of induction of remission [S-01-12630, acute monocytic retaining 8% mod. diff. monocytics]
     • note presence or absence of any apparent M or E stimulant effect...
  3. a new chronic leukemic case, initial diagnostic marrow: approaching the marrow, the case may, so far, be a granulocytosis, mononcytosis or lymphocytosis of uncertain significance vs. leukemia.
  4. a chronic leukemic case, follow-up marrow:
     • CLL:
     • CML: check previous studies and see if evidence of acceleration (increasing blast count; worsening anemia &/or thrombocytopenia)
  5. a (mono-, bi-, odd pan-)cytopenia of uncertain etiology workup: is marrow hypercellular &, if so, leukemia vs. MDS vs. MPS? Is anemic component iron deficient, sideroblastic, or chronic disease pattern?
  6. a probable/possible myeloproliferative (MPS) syndrome workup: is marrow hypercellular (MPS always is)? Is spleen enlarged (MPS almost always)? Is there peripheral basophilic leukocytosis (MPS almost always)?
  7. a probable/possible myelodysplastic (MDS) syndrome workup: is there a PB cytopenia? Is marrow hypercellular (MDS always is...?)? Is there dysplasia of granulation of leukocytes? Dysplasia of megs (hypolobation)? Dysplasia in RBCs (ringed sideroblastosis)? That is, is there unilineage , bilineage, or trilineage dysplasia? Is spleen enlarged (MDS not so)? Is there peripheral basophilic leukocytosis (MDS not so)? Are there findings of "toxicity" such as megakaryocytic vacuoles or poor platelett shedding (favors MDS)?
  8. a thrombocytopenia of uncertain etiology workup: Is it nonproduction or insufficient production ofenough platelets (no BM meg hyperplasia & almost all small PB platelets & spleen not enlarged)? Or, is it increased utilization of platelets (increased BM megs & many intermediate sized PB platelets)? If ITP, see little or no budding of platelets from meg edges & should see meg hyperplasia (in marrow sections, "two megs touching is hyperplasia¹" [S-04-12680]); if due to "toxicity", look for meg vacuoles; if due to MDS, look for meg dyspoiesis. If CBC smear has easily found intermediate-sized platelets, then low count is due to increased "utilization" of platelets.
  9. an anemia of uncertain etiology workup: Iron deficiency? Chronic disease (iron uptake blockade...lots of RES iron and few to no sideroblasts)? Occult myeloma? Granulomata? Hypercellular (leukemia vs. MDS vs. MDS/MPS overlap vs. MPS vs. hemolysis vs. met. ca.) & anemic? Chronic disease anemia might be a coincidental cause of decrease RBCs in a bicytopenia.
  10. MGUS workup: plasma cells increased ("plasmacytosis of uncertain etiology" vs. malignant cytology of myeloma); if increase in plasma cells which are atypical = "atypical plasmacytosis of uncertain etiology" & in somewhere in the report worth noting that the case is otherwise considered "smoldering myeloma" so that at the first finding of a lytic lesion or other corroborating evidence of myeloma, treatment might ensue [S10-6403]?
  11. lymphoma staging marrow: increased lymphoid ( small foci non-paratrabecular benign vs. paratrabecular malignant) or not?
• Significance of some morphological findings:
  1. hypocellular marrow: don't forget to work HARD to discern hypoplastic acute leukemia if present!
  2. hypercellular marrow: (we now see marrows following MRI notation that marrow is hypercellular)
  • paratrabecular included: "medullary hyperplasia" & more concerning that it might non-reactive.
  • paratrabecular sparing: "central medullary hyperplasia" [S09-4139].
  • "hypercellular marrow of undetermined significance": a good "pigeon hole" when extensive study has failed to find an etiology; when no initial etiology obvious and work-up in early stages, "hypercellular marrow of as-yet undetermined significance".
  3. the M:E ratio:
  1. decreased:
  2. normal:
  3. increased:
     1. Neupogen therapy
  • increased presence of mast cells:
    • cytokine therapy, especially Interleukin-3 [S-01-4205]
  • increased presence of megakaryocytes: (when megs touch each other, there are too many)
    • reactive
    • "neoplastic"
      1. reticulin fibers encircle individual megakaryocytes (as in MPS [LMC-01-2306])
      2. abnormal platelet aggregation studies
      3. abnormal cytogenetic studies
  • abnormal trabeculae: keep eyes open for clinically occult histo-morphologic evidence of osteoporosis, Paget's disease, and metabolic disease causing excessive osteoblasts and/or osteoclasts and evidence of trabecular remodeling and/or foci of woven rather than lamellar bone [S-05-9777].

References:

1. Armstrong WR, "pearls"/notes of our own specialist hematopathologist.

(posted 2002; latest addition 16 June 2010)