Practical Application of Bone Marrow Aspiration and Its Interpretation Harold Tvedten Sweden WSAVA, 2001 INDICATIONS FOR BONE MARROW EVALUATION The basic indication for performing a bone marrow evaluation is to answer questions that a routine hematology examination of a blood sample does not answer. One need not take the additional effort to take a bone marrow aspirate and biopsy, if, for example, the blood already clearly indicated an immune mediated hemolytic anemia, a typical inflammatory response, or even a leukemia with clearly diagnostic features in EDTA blood is present. The most common indications for bone marrow analysis are a deficiency of cells from one, two or all three cell lines. Cytopenias suggest decreased bone marrow …ver más…

A histologic section of a biopsy sample gives the best quantitative information on the cellularity of the marrow and reveals meylofibrosis and architectural patterns. All three together usually provide the best information possible. Neglecting one or two parts often leaves unanswered questions. Performing a test several days after the other may also leave some questions.

ANSWERS FROM BONE MARROW EVALUATION The usual answers one gets from bone marrow aspirates and biopsy are quantitative, with morphologic information on the cell lines in the bone marrow. Typical answers include hypoplasia, hyperplasia or normal numbers of myeloid, erythroid, megakaryocytic and lymphoid cells. These changes are then interpreted in conjunction with the cell numbers seen in blood. Additional answers/conclusions/diagnoses are based on the maturity and appearance of the cells examined. Increased immaturity usually indicates a hyperplastic/reactive change unless extreme. Presence of over 30% blast cells indicates an acute leukemia. Hemosiderin amount helps diagnose iron deficiency anemia (absence) or anemia of inflammation (increased). When interpreting a bone marrow report or reading a smear oneself, the first decision should be whether the sample provided adequate cells of sufficient quality to be representative of the bone marrow. Always realize that one is interpreting changes from the norm in a sample and one must first determine if the sample represents the bone marrow