Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
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        Adequacy Of Bone Marrow Examinations:

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While our practice has never calculated or reported "adequacy QA data" as proposed in the 1995 privately published paper arrising out of an attempt at Q Probes, below, we do process all types of organ biopsy specimens thoroughly [HERE]. Our older (1977-1985) process to maximize marrow surface area for histologic viewing is HERE 15 [URL is]. This adequacy page is posted on YouTube (search YouTube using the search term "agar pre-embedding"). The essence of this paper was jointly contemplated for publication in 1974. I was invited in the early 1993 to co-author a Q-probes study for the College of American Pathologists in order to assess the status of bone marrow examinations within pathology departments throughout the United States. The effort was discontinued when significant institutional concern mounted up that the write-up could potentially be misused as representing a "standard of care document". Having missed that chance to trigger a published debate as to adequacy of bone marrow examination, I initially offered the below write up of a potential assessment process and some commentary, especially in light of the 1990s managed-care mentality that less work/effort is better and more cost effective.


[I updated the following paper, copyrighted by our group in 1995, in about 2000 & have misplaced that update; I additionally tweaked the paper in 2014]

When Is Enough Enough?


Any bone marrow examination which accurately pinpoints one or more significant diagnoses (whether a one-smear or comprehensive exam) must be considered to be at least a partially adequate bone marrow examination. Ideally, the approach to, and comprehensiveness of, a bone marrow exam would be planned through the collaboration of the clinical physician and the pathologist (morphologist interpreter) in view of resources and the differential diagnosis or management question in the particular patient. Clinical history helps to focus the exam to answer specific, implied questions. Short of such, an array of techniques are variably applied in different practice settings. A routine optimal approach broadly applicable to general (and specialty) pathology practice has been previously described1,17, having been utilized in that institution for over 30 years. It has worked well in our lab since 1984.

Most diagnostic situations can be bracketed, even highly specifically diagnosed, on a routine, properly acquired, comprehensive, technically well-processed bone marrow specimen along with peripheral blood data and smear. Special studies are also easily feasible, especially when preplanned, on such a sample. Otherwise, a special-purposes specimen is needed. In the USA, such well-done specimens are only 48 hours removed from world-class expert consultation, should such become desired.

The morphologic state of hematopoiesis is most consistently and reliably interpreted when smears of (1) peripheral blood and (2) bone marrow (cytologic manifestations) are compared with (3) sections of marrow (histologic manifestations [a] within intact trphine cores or [b] within particle aggregates HERE) and interpreted by a physician trained in morphologic hematology.17 Yet, in an individual patient encounter, these three standard preparations of the morphology of hematopoiesis (peripheral blood smears, marrow smears, marrow sections) are sometimes subject to split interpretations, each component reviewed by different persons (located even in different geographic locations) with varying expertise. In view of the adult hematopoietic system being a 1600-3700 gram organ, sample adequacy often is suboptimal, especially in the search for focal disease. MRI has the capability of adding to marrow assessment; ultrasound exams can quickly/accurately detect splenomegaly. Intuitively, the patient would be best served when this specialized morphologic interpretation and results of other specialized studies are collated (unified) into a final comprehensive report, a report detailing the study adequately.7,8,11 Knowledge of specifics of original malignancy diagnoses may be critical in optimizing workups and diagnostic consultation.9,16 Turnaround time for preliminary and final reporting deserves attention.


One might measure group performance within a single practice or, more broadly, by a large multi-practice survey retrospectively assessing 30 completed bone marrow studies with one or more of 10 diagnoses (to include diffuse and focal disease) and responses to a series of questions. Quantity or total surface area of bone marrow examined is especially important for detecting focal disease.5,6 [note = a no-longer-used by our pathology group technique because our pathologists don't perform the obtaining of marrow...HERE] Comprehensiveness of the bone marrow exam can be more generally calculated as follows (since the weighting of any particular element of the formula would vary by the final diagnosis, the formula is unweighted):


Clinical Data:
1 point if yes 1. Does the report reflect the prime indication for the bone marrow exam?
1 point if yes 2. Does the report reflect availability of pertinent clinical data?
1 point if yes 3. Does the report reflect availability/consideration of relevant lab data?


Peripheral Blood Data:
1 point if yes 1. Was a peripheral blood smear reviewed?
1 point if yes 2. Were WBC, RBC, and platelet counts known?
1 point if yes 3. Was a reticulocyte count known (and/or prep reviewed)?


Bone Marrow Cytology Data:
1 point if yes 1. Was an aspirate particle smear reviewed?
1 point if yes 2. Was a smear of centrifuged aspirate buffy coat layer reviewed? 
1 point if yes 3. Was a biopsy touch prep reviewed?


Bone Marrow Histology Data:
1 point if yes 1. Was a trephine (or equivalent) biopsy reviewed?
1 point if yes 2. Was a particle cell block or clot section reviewed?
E. Ancillary Studies Data:
1 point if yes 1. Was an iron stain done at all?
1 point if yes 2. Was an iron stain done on both cytological and histological preps?
1 point if yes 3. If highly specialized studies were done does the report document it?
F. Evidence of Collated Unified Report/Interpretation
1 point if yes 1. Is it clearly evident from the report that all information was correlated into an interpretation resulting in the final diagnosis?


The total number of points is added in order to give a "comprehensiveness score" for the case. Mean, median, and mode calculations are derived from the 30 cases in order to calculate a comprehensiveness score for the group; likewise, such parameters could be calculated for co-operating groups of labs or pathologist groups.

Thusly, the highest comprehensiveness score for a case is 15 points, the sum of all of the above points (realizing that this can still seriously under-estimate the intensity of effort on a given case). While intensity of effort is ultimately related to case difficulty plus the personality (sense of perseverance and compulsion) of the interpreting morphologist, we have attempted to formulate a way to portray an institutional or group commitment to intensity of effort through a combination of the comprehensiveness score and the average number of varieties of slide preparations per bone marrow case presented to the morphologist, the "low" category not at all taken to necessarily mean inadequate:

1 point. Limited/focal intensity = less than low intensity.
2 points. Low intensity = 3 or more preps (1 each of peripheral blood, bone marrow cytology, bone marrow histology).
3 points. Medium intensity = 8 or more preps (1 each of peripheral blood, peripheral blood retic smear, bone marrow cytology particle aspirate, bone marrow cytology buffy coat concentrate smear, bone marrow biopsy touch prep, 3 step-cuts of bone marrow histology, iron stain of a particle aspirate smear).
4 points. Highest intensity = 15 or more (medium intensity plus: 3 step-cuts of particle aspirate cell block or clot section and iron stains on all four of centrifuged aspirate fat layer smear, centrifuged aspirate buffy coat layer smear, and both trephine and cell block/clot histologic samples).

An institutional or group practice commitment to "thoroughness" can then be numerically expressed using a double number: a comprehensiveness number of 15 and a medium intensity number of 3 would be expressed as a "thoroughness number" of 15/3.

Is medium, much less highest intensity, effort worth the time, energy and expense? In our practice, this highest intensity (4 points) effort breaks out as follows with increased increment estimates:

a. Medical technologist time increment per case beyond "low": estimated at 30-45 minutes, actual technologist time.

b. Histotech time increment per case beyond "low": estimated at 15 minutes actual technologist time.

c. Pathologist/morphologist time increment per case beyond "low": 5-10 minutes actual time.

Specimen: Once into the routine, thoroughness is as easy to carry out as non-thoroughness. And, the many possible artifacts induced in marrow are more likely to be interpretatively compensated for in a thorough exam. Aspirates can be faulty by in vitro clotting or peripheral blood dilution, or by smears being too thick or improperly fixed and stained. The slides of a 1 or 2 slide case can break or be lost. If one aspirates and then biopsies from the aspirate site (or very closely nearby), there is a risk of confusion through intramedullary hemorrhage or negative-pressure evacuative disruption.2,18 We recommend biopsy first followed by aspiration from a second, even nearby site.6,17,18 Trephine biopsies in older patients often show a naturally hypocellular 2-4 mm subcortical fatty zone2; the particle cell block or clot section may compensate by showing deeper, cellular marrow. Whereas B5 fixative is the fixative of choice for bone marrow immuno-staining and general morphology3, B5 and the decalcification process can leach stainable iron out of the specimen (we continue to use a mercury-based fixative [in about 2013, we switched to GI-Fix [zinc-formalin] by BBC). Smears for iron stain from aspirates left in EDTA too long may also under-represent iron stores due to iron leaching. The centrifuged aspirate fat layer smear reflects reticulo-endothelial iron; and we have found this to be a significantly positive preparation when iron stores appear, by comparison, to be much less (or even absent) in the other types of preparations. Routine paraffin-embedded processing is preferred.2,4 I have found different smear fixation methods to cause significant variations in apparent iron content and sideroblasts percentages, more so than expected. This can be problematic in the discrimination between iron positive bone marrow with low sideroblast count indicating the impaired uptake of chronic disease anemia versus marrows which are otherwise non-iron-poor: so, is the sideroblast percentage actually normal or reduced?14 Iron content grading systems exist.18

Finally, until proven to the contrary, the old axiom "it is better to have it and not need it than to need it and not have it" applies: don't throw anything away before the case is fully signed out! For example, a particle cell block fixed in B5 fixative using aspirated marrow in an EDTA tube left out overnight at room temperature can, in a pinch, give information as to cellularity or presence of a granuloma or metastatic malignancy.

Our hemato-oncologists obtain Jamshidi trephine biopsy cores: the average non-staging marrow biopsy is 0.9 cm long; and staging marrows average 1.2 cm long. A 1.5 to 2.0 cm trephine core is generally considered adequate11 to optimal7,17 and less than adequate if shorter than 1 cm (unless it results in a pertinent positive diagnosis).10,18 At least in the case of diffuse large cell lymphoma, bilateral sampling has shown that positivity occurs in only one of the two biopsies in 50% of cases.9 A negative staging marrow is best considered to be a "true negative" when sampling two sites, each yielding the equivalent of a trephine core 2 x 0.2cms19 (and special marker stains and other parameters being negative, as previously discussed). This thoroughness is even proposed as cost effective.20 The most accurate assessment of bone marrow cellularity8 and proper architectural geographic location of cell lines is by way of the bone marrow biopsy specimen. Logically, a search for focal disease would imply the need of an examination of a greater quantity (histological surface area) of bone marrow than evaluation of diffuse systemic disease. Again, bilateral staging biopsies have long been recommended in lymphoma staging.6,13 Immunoperoxidase markers can label minimal but significant infiltrates of lymphoma,12 lobular carcinoma,16and minimal myeloma.21 Only using routine studies can result in false-negative diagnosis in a dismal 61% of lobular carcinoma cases!16 Acute leukemia evaluations post-chemotherapy are best done with the trephine biopsy where geographic presence of immature cells in paratrabecular regions is more likely to reflect regeneration whereas such foci in medullary regions may reflect residual/recurrent leukemia.22 In the search for focal disease, cell block aggregation of ordinary aspirate residual or, better, a special aspirate to provide a large cell block,15 can greatly increase bone marrow surface area examined. Maneuvers to wash RBCs from the cell block particle aggregate will make sectioning easier and remove the RBC source of background peroxidases.15

Tissue culture, microbiological culture, cytogenetic studies, flow cytometry studies, and other special studies are extremely difficult to generally anticipate and cover for in a routine bone marrow examination (collaboration is even more important in such cases).

A high quality and thorough morphologic interpretation of bone marrow has the potential for addressing hematological (and some other disease categories, too) differential diagnoses more completely than can be obtained through both direct and inferential information garnered through other laboratory and clinical tests. A rapid preliminary review of peripheral blood and bone marrow smears may be able to answer the bottom-line, highly focused question of the clinician. If the clinician thusly is supported with rapid preliminary diagnosis turn-around times followed by a comprehensive bone marrow diagnostic sign-out within 48 hours or less, the bone marrow is likely to become a more worthwhile and frequently used component of clinical workups. Our sense of pathologist-clinician colleagueness is enhanced; and patient care decisions made quicker with rapid turn-around time, especially in situations such as: rule out acute leukemia, thrombocytopenia, and pancytopenias. We are aware that rapid turn-around time is becoming increasingly important in many pathology practices.

The Bethesda System for pap smear reporting has (under the CLIA regulations) forced pathologists and gynecologists to address the issue of specimen/history adequacy of a pap smear. It is hoped that this write-up will encourage physicians to begin to define the adequacy of a particular bone marrow exam in view of the clinical indication for the exam as well as the statistical information uncovered in evaluating thoroughness in your pathology practices. Unlike the massive increase in intensity needed to achieve 100% oxygen saturation of hemoglobin, thoroughness in morphologic hematology is easy once beyond the initial stage of gearing up and systematizing the process.


1. R.K. Brynes, R.W. McKenna, R.D. Sundberg, Bone Marrow Aspirate and Trephine Biopsy: An Approach to a Thorough Study, American Journal of Clinical Pathology, 1978, 70(5): 753-759, HERE.

2. R.D. Brunning in Ackerman's Surgical Pathology, 7th Ed., Juan Rosai, The C.V. Mosby Co., 1989, Chapter 23, pgs. 1379- 1453.

3. R.D. Brunning at Mayo Medical Laboratories Conference: Hematopathology Updates, Scottsdale, Ariz. 24 Sept. 1993,

4. K.C. Gatter, A. Heryet, D.C. Brown, D.Y. Mason, Is It Necessary to Embed Bone Marrow Biopsies in Plastic For Hematological Diagnosis?, Histopathology, 1987, 11:1-7, HERE.

5. B.A. Chabner, R.I. Fisher, R.C. Young, V.T. DeVita, Staging of non-Hodgkin's Lymphoma. Seminars in Oncology, Sept. 1980, 7(3):285-291, HERE.

6. R.D. Brunning, C.D. Bloomfield, R.W. McKenna, and L. Peterson, Bilateral Trephine Bone Marrow Biopsies in Lymphoma and Other Neoplastic Diseases. Annals of Internal Medicine, 1975, 82:365-366, HERE.

7. J. R. Krause, Bone Marrow Biopsy, 1981, Churchill Livingstone, 232 pages.

8. J.I. Dickstein & J.W. Vardiman, Issues in the Pathology and Diagnosis of the Chronic Myeloproliferative Disorders and the Myelodysplastic Syndromes, AJCP 99(4): 513-525, April 1993, HERE.

9. G.F. Hodges,, Bone Marrow Involvement in Large-cell Lymphoma, Prognostic Implications of Discordant Disease, AJCP, 101(3):305-311, March 1994, HERE.

10. C.L. Wright, & K. Rizkalla, Bone Marrow Biopsy Length in Staging of Lymphomas, Modern Pathology, 1994, 7(1): 124A, 1994.

11. B.H. Hyun,, Bone Marrow Examination: Techniques and Interpretation, in Hematology/Oncology Clinics of North America, 2(4):513-523, 1988, HERE.

12. M. Fraga,, Bone Marrow Involvement in Anaplastic Large Cell Lymphoma..., AJCP, 103(1): 82-89, 1995, HERE.

13. J.A. Hinson & M.C. Perry, Small Cell Lung Cancer, CA Cancer Journal for Clinicians, 43(4): 216-225, 1993, HERE.

14. R.D. Sundberg & H. Browman, The Application of the Prussian Blue Stain to Previously Stained Films of Blood and Bone Marrow, Blood, 10:160-166, 1955, HERE.

15. E.B. Shaw, Agar Processing of Bone Marrow Aspirate Material, Laboratory Medicine, 25(1):39, 1993, HERE.

16. M.A. Bitter,, Bone Marrow Involvement by Lobular Carcinoma of the Breast Cannot Be Identified Reliably by Routine Histologic Examination Alone, Human Pathology, 25(8): 781-788, 1994, HERE.

17. R.D. Brunning & R.W. McKenna, Atlas of Tumor Pathology...Tumors of the Bone Marrow (AFIP 3rd Series Fascicle 9), Armed Forces Institute of Pathology, Washington, D.C., 1994, 496 pages.

18. G.R. Lee,, Wintrobe's Clinical Hematology, 9th Ed., Lea & Febiger, 1993, 2324 pages.

19. R.W. McKenna & J.A. Hernandez, Bone Marrow in Malignant Lymphoma, in Hematology/Oncology Clinics of North America, 2(4):617-635, 1988, HERE.

20. G.E. Richardson,, Application of an Algorithm for Staging Small-Cell Lung Cancer Can Save One-Third of the Initial Evaluation Costs, Archives of Internal Medicine, 153(3):329-337, 1993, HERE.

21. D. M. Menke,, Bone Marrow Aspirate Immunofluorescent and Bone Marrow Biopsy Immunoperoxidase Staining of Plasma Cells in Histologically Occult Plasma Cell Proliferative Marrow Disorders, Archives of Pathology and Laboratory Medicine, 118(8): 811-814, August, 1994, HERE.

22. J.H. Beckstead, The Bone Marrow Biopsy: A Diagnostic Strategy, Archives of Pathology and Lab Medicine, 110(3):175-9, March 1986, HERE.

23. S.S. Sung, Immuno-architecture of Normal Human Bone Marrow: A study of frozen and fixed tissue sections, Human Pathology, 23(6): 686-694, June 1992, HERE.

Ervin Shaw, M.D. (and with thanks to John B. Carter, M.D. for his mentorship); 2/95 (distributed at April 1995 CAP/ASCP meeting in Orlando, Florida, USA)

Lexington Medical Center

2720 Sunset Blvd.

West Columbia, SC 29169-4810

Note: Pathology Associates of Lexington, P.A. at Lexington Medical Center, West Columbia, S.C. has long utilized this above approach to hematology workups and bone marrow processing [HERE] and interpretation. (proofed 6 February 2017)

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