Which of the following patients would LEAST likely require a bone marrow examination?
An adult with fever and a white blood cell count of 20,000 cells/l with a left shift has an infection, which is not an indication for a bone marrow examination. Pancytopenia; documenting a myeloproliferative disease; ruling out multiple myeloma as the cause of a monoclonal spike; and evaluating a child with the fever, bone pain, anemia, thrombocytopenia, and an increased lymphocyte count for possible acute lymphoblastic leukemia are all valid indications for a bone marrow examination. Other indications include the work-up of metastatic disease to bone and staging for Hodgkin and non-Hodgkin lymphomas. As a general rule, bone marrow aspirates/biopsies are not usually necessary in: Diagnosing iron deficiency or anemia of chronic disease, because iron studies are adequate Thalassemia syndromes, because hemoglobin electrophoresis is the gold standard test B12 or folate deficiency, because Bib red blood cell folate, and serum folate levels are usually sufficient Hemolytic anemias, because the reticulocyte count (marker for all hemolytic anemias), the direct and indirect Coombs test (autoimmune anemias), osmotic fragility (congenital spherocytosis), Heinz body preparations (glucose-6-phosphate dehydrogenase deficiency), and hemoglobin electrophoresis (sickle cell and its variants) are sufficient in most cases Most bone marrow examinations are performed on the posterior iliac crest, since both a bone marrow aspirate and biopsy may be obtained in this area. A "dry tap" means that nothing was obtained on the bone marrow aspirate. A "dry tap" may be due to faulty positioning of the needle (most common cause), a marrow packed with cells (leukemia), a marrow replaced by fibrous tissue (agnogenic myeloid metaplasia and myelofibrosis secondary to metastatic disease), or anaplastic marrow. Normal components of a bone marrow examination and repo include: An evaluation of cellularity. Normally, there is an approximately 30% fat to 70% cell ratio (varies with age). Calculation of the myeloid to erythroid ratio, which is normally 3: 1 An evaluation of hematopoietic cell morphology and adequacy of numbers of megakaryocytes (platelet production) An estimate of the status of marrow iron stores with the Prussian blue stain. Absent iron characterizes iron deficiency; excess iron the anemia of chronic inflammation; and ringed sideroblasts, a sideroblastic anemia. Ref - Harrison's principles of internal medicine 20e , pubmed.com
Adult with pancytopenia and a normal mean corpuscular volume
Adult with a myeloproliferative disease
Adult with a monoclonal spike on a serum protein electrophoresis
Adult with fever and a WBC of 20,000 cells/l with a left shift
Haematology