Hematology Oncology · Year 2 · from Hematology Oncology
Case 1: Aplastic Anemia - Bone Marrow Failure
Patient Presentation
Demographics: 28-year-old female
Chief Complaint: Progressive fatigue, easy bruising, and recurrent infections over 3 months
History of Present Illness: The patient reports gradually worsening fatigue that now limits her daily activities. She has noticed increasing bruising on her extremities with minimal trauma and has had two episodes of prolonged nosebleeds. She was treated for a urinary tract infection 6 weeks ago and developed sinusitis 2 weeks ago requiring antibiotics. She denies any recent viral illness, new medications, or toxic exposures.
Physical Examination:
- Vital signs: BP 110/70, HR 92, RR 16, Temp 37.2C
- General: Pale-appearing young woman
- Skin: Multiple ecchymoses on arms and legs, petechiae on lower extremities
- HEENT: Conjunctival pallor, no lymphadenopathy
- Cardiac: Tachycardic, systolic flow murmur
- Abdomen: No hepatosplenomegaly
- Neurologic: Normal
Workup and Results
Complete Blood Count:
- WBC: 1,800/uL (normal 4,500-11,000)
- Absolute Neutrophil Count: 400/uL
- Hemoglobin: 7.2 g/dL (normal 12-16)
- MCV: 102 fL
- Platelets: 18,000/uL (normal 150,000-400,000)
- Reticulocyte count: 0.3% (inappropriately low)
Peripheral Blood Smear:
- Pancytopenia confirmed
- No abnormal cells or blasts
- Normochromic, slightly macrocytic red cells
Bone Marrow Biopsy:
- Markedly hypocellular (cellularity <10%)
- Fat replacement of hematopoietic tissue
- No dysplasia or malignant infiltrate
- Residual lymphocytes and plasma cells
Clinical Image
Bone marrow biopsy showing severely hypocellular marrow with fat replacement in aplastic anemia. Image source: Wikimedia Commons. License: CC BY-SA 3.0
Diagnosis
Severe Aplastic Anemia
Diagnostic criteria met:
- Bone marrow cellularity <25%
- At least 2 of 3: ANC <500/uL, platelets <20,000/uL, reticulocyte count <1%
Treatment Plan
- Supportive care:
- Transfusion support (leukoreduced, irradiated products)
- Infection prophylaxis with antibacterials and antifungals
- Definitive therapy:
- Age <40 with matched sibling donor: Allogeneic hematopoietic stem cell transplantation (preferred)
- No donor available: Immunosuppressive therapy with antithymocyte globulin (ATG) + cyclosporine
- Growth factor consideration:
- Eltrombopag may be added to IST to improve response rates
Teaching Points
- Aplastic anemia represents bone marrow failure affecting all three cell lineages (pancytopenia)
- The bone marrow is hypocellular (unlike MDS or acute leukemia which are typically hypercellular)
- Reticulocyte count is inappropriately low, indicating production problem rather than peripheral destruction
- Young patients with matched sibling donors should be offered transplant as first-line therapy
- Understanding normal hematopoiesis helps recognize when stem cell function fails