HematoCredentials & Recognitions
Board Certified
Internal Medicine
Hematology Fellow
ABIM Subspecialty
ASH Member
Am. Society of Hematology
Published Research
Blood Journal · NEJM
Top Hematologist
US News Health 2024–25
NCI Affiliate
Oncology Network
MDS Foundation
Clinical Advisory Board
18+ Years Practice
Diagnostic Hematology
When the bloodwork
raises questions,
we provide the
diagnosis.
Board-certified hematologist specializing in cases that defy easy explanation — persistent cytopenias, unexplained clotting, and the CBC that has been flagged three times without an answer.
3,400+
Cases resolved
18 yrs
Clinical practice
48 hrs
Report turnaround
Complete Blood Count
Patient Report #2847
Specialist Finding
"Pancytopenia with macrocytosis — MDS workup indicated"
Referral Note
"CBC flagged ×3. Fatigue, bruising. No diagnosis offered."
→ MDS Panel ordered
Resolved
MDS-SLD confirmed. Treatment initiated. Patient stable at 6 months.
The Referral That Brought You Here
Recognize your case in one of these?
These are the referrals that arrive without a diagnosis. Each one has a pathway. Each one has an answer.
Persistent Cytopenias
Common Referral"My CBC has been low for eight months and no one can tell me why."
A 52-year-old woman with fatigue and easy bruising. Three CBCs showing mild pancytopenia. Bone marrow biopsy not yet ordered.
MDS workup → bone marrow biopsy → cytogenetics
Unexplained Clotting
Urgent Referral"Second DVT in two years. Hematology was never consulted."
A 38-year-old man with recurrent DVT, no obvious provoking factors, family history of clotting. Hypercoagulable workup incomplete.
Hypercoagulable panel → genetic counseling → anticoagulation protocol
Post-Treatment Monitoring
Ongoing Care"Finished chemotherapy six months ago. Counts still haven't normalized."
A 61-year-old man post-CHOP for DLBCL. Persistent neutropenia, recurrent infections, oncologist requesting hematology co-management.
Recovery assessment → bone marrow reserve testing → supportive protocol
Unexplained Fatigue
Diagnostic Challenge"Profound fatigue for a year. Iron studies and thyroid are normal."
A 47-year-old woman with debilitating fatigue, mild macrocytosis, and B12 in the low-normal range. Primary care has exhausted first-line workup.
Megaloblastic anemia panel → intrinsic factor Ab → methylmalonic acid
Don't see your situation? Every case begins with a conversation.
Start with the Blood Health ScreenerDiagnostic Pathways
From first panel to final answer
Each condition has a defined investigative arc. We follow it with precision, not guesswork.
Iron Deficiency Anemia
The most common anemia — but the cause is never trivial.
Myelodysplastic Syndromes
Clonal disease masquerading as routine cytopenia.
Inherited Coagulopathies
When clotting or bleeding runs in the family.
Myeloproliferative Neoplasms
Polycythemia vera, ET, and myelofibrosis require lifelong precision.
Hematology practiced with the patience of a diagnostician and the precision of a researcher.
Diagnostic Method
Precision Analysis
Research
Published Science
Dr. Margaret Osei-Bonsu, MD
Fellowship-trained at Memorial Sloan Kettering. 18 years of consultative hematology. Accepts referrals from internists, oncologists, and self-referring patients.
Selected Publications
JAK2 mutation burden and thrombotic risk in polycythemia vera
Hypomethylating agent response in MDS with complex karyotype
Ferritin threshold optimization in iron deficiency screening
Clinical Symptom Screener
Check Your Blood Health
Five questions. Two minutes. A personalized risk category and a clear next step.
Question 1 of 5
0%
How long have you been experiencing unusual fatigue or weakness?
Fatigue that doesn't improve with rest or sleep.
This screener is for informational purposes only and does not constitute medical advice. Results are not a diagnosis. Please consult a licensed physician for any health concerns.
Patient Outcomes
Cases that ended with a definitive answer
Every case journal entry ends the same way: with resolution, a treatment plan, and a patient who finally knows.
Myelodysplastic Syndrome
Three hematologists said "watch and wait." Dr. Osei-Bonsu ordered the bone marrow biopsy on day one of our consultation. We had a diagnosis in two weeks.
Margaret T., 67
Upper East Side, New York
MDS-SLD confirmed. ESA therapy initiated. Transfusion-independent at 4 months.
Inherited Thrombophilia
I was on lifelong anticoagulation based on a guess. The full hypercoagulable panel showed it was heterozygous Factor V — not the same risk profile at all.
David K., 38
Brooklyn, New York
Anticoagulation duration revised to 3 months. Surveillance protocol established. No recurrence at 18 months.
Polycythemia Vera
My cardiologist kept treating my high hematocrit as a lifestyle issue. One referral to Hemato and a JAK2 test later — it had a name, and it had a treatment.
Richard A., 59
Manhattan, New York
JAK2+ PV confirmed. Phlebotomy + hydroxyurea. Hematocrit stable at 43% for 2 years.
Your case deserves the same resolution.
Whether you're a patient who has been waiting months for an answer, or a physician who has reached the edge of your workup — the next step is a single consultation.
Understanding Your CBC
A patient guide to the six values that matter most — what they measure, what's normal, and what a flag actually means.
White Blood Cells
Normal: 4.5–11.0 K/μL
Immune defense. Elevated in infection; low in bone marrow suppression or autoimmune disease.
Red Blood Cells
Normal: 4.2–5.4 M/μL
Oxygen transport. Reduced in anemia; elevated in polycythemia vera.
Hemoglobin
Normal: 12.0–17.5 g/dL
The primary oxygen carrier. The most clinically significant anemia indicator.
Mean Corpuscular Volume
Normal: 80–100 fL
Red cell size. High = macrocytic (B12/folate). Low = microcytic (iron deficiency).
Platelets
Normal: 150–400 K/μL
Clotting cells. Low raises bleeding risk; elevated may indicate MPN or reactive thrombocytosis.
Absolute Neutrophil Count
Normal: >1.5 K/μL
Infection-fighting neutrophils. Critical threshold for chemotherapy patients and MDS monitoring.
Get the full 12-page PDF guide
Includes reference ranges, flag interpretations, and questions to ask your doctor.
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